Citation Rankings
Highly Cited Researchers
Highly Cited Researchers Citation Rankings 2025
The Citation Rankings (Highly Cited Researchers) highlight the most cited and influential researchers across a vast range of scientific fields, covering 197 main and sub-disciplines, including the Art and Humanities Citation Rankings and Social Sciences and Humanities Citation Rankings. This service, offered exclusively by AD Scientific Index, aims to provide a balanced perspective by excluding data from CERN and other statistical sources that disproportionately favor certain researchers, particularly in the social sciences and humanities. This unique approach addresses the advantages researchers with multi-author publications and CERN involvement hold over others. Furthermore, citation rankings help uncover rule violations and unethical practices within the research community. For more detailed citation analyses, explore the Scientists Last 6 Years Citation Index, Universities Total Citations Rankings 2025, and Universities Last 6 Years Citations Rankings 2025.
* Total Citation Counts Rankings
Ranking Based On Selection :1
nanophosphors
luminescence
cathodoluminescence
surface characterization
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
26,267
17,900
0.681
* Total Citation Counts Rankings
Ranking Based On Selection :2
Water resources management
Water accounting
Water Footprint
Food
Irrigation
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
22,297
9,098
0.408
* Total Citation Counts Rankings
Ranking Based On Selection :3
Physics
Astrophysics
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
14,510
9,489
0.654
* Total Citation Counts Rankings
Ranking Based On Selection :4
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
11,250
6,025
0.536
* Total Citation Counts Rankings
Ranking Based On Selection :5
Pollen analysis
palaeoscience
palynology
palaeoecology
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
10,795
3,606
0.334
* Total Citation Counts Rankings
Ranking Based On Selection :6
higher education and development
social justice
development ethics
capability approach
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
10,607
5,010
0.472
* Total Citation Counts Rankings
Ranking Based On Selection :7
Chemistry
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
8,542
5,162
0.604
* Total Citation Counts Rankings
Ranking Based On Selection :8
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
8,184
3,851
0.471
* Total Citation Counts Rankings
Ranking Based On Selection :9
Virology
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,466
6,937
0.929
* Total Citation Counts Rankings
Ranking Based On Selection :10
Phytochemistry
Nutraceuticals
Natural Product Research
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,199
6,810
0.946
* Total Citation Counts Rankings
Ranking Based On Selection :11
Perovskite solar cell
Organic solar cell
DSSC
Gas Sensors
Materials for Energy
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,113
4,500
0.633
* Total Citation Counts Rankings
Ranking Based On Selection :12
Biostatistics
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,617
1,468
0.222
* Total Citation Counts Rankings
Ranking Based On Selection :13
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,566
5,646
0.860
* Total Citation Counts Rankings
Ranking Based On Selection :14
Stable isotope ecology
Wildlife ecology
Evolutionary ecology
Palaeoecology
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,229
3,057
0.491
* Total Citation Counts Rankings
Ranking Based On Selection :15
Food Science
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,113
3,656
0.598
* Total Citation Counts Rankings
Ranking Based On Selection :16
Reliability theory-stochastic modeling
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,925
3,366
0.568
* Total Citation Counts Rankings
Ranking Based On Selection :17
Yeast Taxonomy
Signal trasnduction
Pathogenic yeasts
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,544
1,537
0.277
* Total Citation Counts Rankings
Ranking Based On Selection :18
coordination chemistry
reaction mechanisms
crystallography
catalysis
radiopharmacy models
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,175
1,263
0.244
* Total Citation Counts Rankings
Ranking Based On Selection :19
Organic Chemistry
Nano Science
Clinical Biochemistry
Exosomes
Extracellular Vesicles
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,729
4,249
0.898
* Total Citation Counts Rankings
Ranking Based On Selection :20
medicine
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,595
1,579
0.344
* Total Citation Counts Rankings
Ranking Based On Selection :21
housing
small towns
mining towns
public health
children
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,101
2,521
0.615
* Total Citation Counts Rankings
Ranking Based On Selection :22
ferrocene
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,055
1,042
0.257
* Total Citation Counts Rankings
Ranking Based On Selection :23
Plant Pathology
soil ecology
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,044
1,929
0.477
* Total Citation Counts Rankings
Ranking Based On Selection :24
Organometallic chemistry
Corrosion
Material Chemistry
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
3,849
2,124
0.552
* Total Citation Counts Rankings
Ranking Based On Selection :25
Health
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
3,839
1,177
0.307
* Total Citation Counts Rankings
Rankings
27,423
74
1
Ranking Based On Selection: 1
HC Swart
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
26,267
17,900
0.681
nanophosphors
luminescence
cathodoluminescence
surface characterization
* Total Citation Counts Rankings
Rankings
34,770
107
2
Ranking Based On Selection: 2
Ashok Chapagain
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
22,297
9,098
0.408
Water resources management
Water accounting
Water Footprint
Food
Irrigation
* Total Citation Counts Rankings
Rankings
62,399
210
3
Ranking Based On Selection: 3
Petrus Johannes Meintjes
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
14,510
9,489
0.654
* Total Citation Counts Rankings
Rankings
85,798
292
4
Ranking Based On Selection: 4
M Gryzenhout
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
11,250
6,025
0.536
* Total Citation Counts Rankings
Rankings
90,151
311
5
Ranking Based On Selection: 5
Louis Scott
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
10,795
3,606
0.334
Pollen analysis
palaeoscience
palynology
palaeoecology
* Total Citation Counts Rankings
Rankings
92,080
319
6
Ranking Based On Selection: 6
Melanie Walker
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
10,607
5,010
0.472
higher education and development
social justice
development ethics
capability approach
* Total Citation Counts Rankings
Rankings
117,776
442
7
Ranking Based On Selection: 7
Jeanet Conradie
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
8,542
5,162
0.604
* Total Citation Counts Rankings
Rankings
123,575
462
8
Ranking Based On Selection: 8
Felicity Burt
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
8,184
3,851
0.471
* Total Citation Counts Rankings
Rankings
136,608
537
9
Ranking Based On Selection: 9
Dominique Goedhals
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,466
6,937
0.929
* Total Citation Counts Rankings
Rankings
142,043
560
10
Ranking Based On Selection: 10
Abhay Prakash Mishra
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,199
6,810
0.946
Phytochemistry
Nutraceuticals
Natural Product Research
* Total Citation Counts Rankings
Rankings
143,885
567
11
Ranking Based On Selection: 11
Vinod Kumar
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
7,113
4,500
0.633
Perovskite solar cell
Organic solar cell
DSSC
Gas Sensors
Materials for Energy
* Total Citation Counts Rankings
Rankings
155,169
610
12
Ranking Based On Selection: 12
Robert Schall
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,617
1,468
0.222
* Total Citation Counts Rankings
Rankings
156,386
612
13
Ranking Based On Selection: 13
Diederik J Opperman
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,566
5,646
0.860
* Total Citation Counts Rankings
Rankings
165,117
655
14
Ranking Based On Selection: 14
Daryl Codron
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,229
3,057
0.491
Stable isotope ecology
Wildlife ecology
Evolutionary ecology
Palaeoecology
* Total Citation Counts Rankings
Rankings
168,265
672
15
Ranking Based On Selection: 15
Arno Hugo
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
6,113
3,656
0.598
* Total Citation Counts Rankings
Rankings
173,524
698
16
Ranking Based On Selection: 16
Maxim Finkelstein
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,925
3,366
0.568
Reliability theory-stochastic modeling
* Total Citation Counts Rankings
Rankings
185,298
766
17
Ranking Based On Selection: 17
Jacobus Albertyn
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,544
1,537
0.277
Yeast Taxonomy
Signal trasnduction
Pathogenic yeasts
* Total Citation Counts Rankings
Rankings
198,118
819
18
Ranking Based On Selection: 18
Andreas Roodt
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
5,175
1,263
0.244
coordination chemistry
reaction mechanisms
crystallography
catalysis
radiopharmacy models
* Total Citation Counts Rankings
Rankings
216,163
905
19
Ranking Based On Selection: 19
Anand Krishnan
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,729
4,249
0.898
Organic Chemistry
Nano Science
Clinical Biochemistry
Exosomes
Extracellular Vesicles
* Total Citation Counts Rankings
Rankings
222,120
936
20
Ranking Based On Selection: 20
S Brown
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,595
1,579
0.344
* Total Citation Counts Rankings
Rankings
246,720
1,044
21
Ranking Based On Selection: 21
Lochner Marais
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,101
2,521
0.615
housing
small towns
mining towns
public health
children
* Total Citation Counts Rankings
Rankings
249,306
1,060
22
Ranking Based On Selection: 22
Jannie Swarts
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,055
1,042
0.257
* Total Citation Counts Rankings
Rankings
249,892
1,063
23
Ranking Based On Selection: 23
Wijnand Swart
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
4,044
1,929
0.477
* Total Citation Counts Rankings
Rankings
261,164
1,113
24
Ranking Based On Selection: 24
Sumit Kumar
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
3,849
2,124
0.552
Organometallic chemistry
Corrosion
Material Chemistry
* Total Citation Counts Rankings
Rankings
261,784
1,119
25
Ranking Based On Selection: 25
HCJ Van Rensburg
University of the Free State
Bloemfontein, South Africa
Citation Metrics
Total
Last 6 Years
Last 6 Years / Total
3,839
1,177
0.307