His papers were cited over 17000 times, and in the last 10 years he has published 15 Highly Cited Papers according to
Essential Science Indicators of the Web of Science.
A paper on the portal, published in the Journal of chemical information and modeling, was recently cited as a «hot paper» by
Essential Science Indicators, a major scientific database.
According to the ISI
Essential Science Indicators, Holland was one of the top 10 most - cited countries from 1993 - 2003 (6th place), with only England, Germany, France, and Italy ahead of it in Europe.
Science Watch, a review of the Web research tool
Essential Science Indicators, found a decline in U.S. representation among the world's published scientific papers, dropping from 38.5 percent in 1990 to 33.3 percent in 2004.