Subjects We Know About - True Knowledge Protected by US patents 7,013,308 and 7,707,160. Other US and international patents pending. http://www.trueknowledge.com/subjects/J/600/
Topologists Topics At Duck Duck Go Johannes De Groot Johannes de Groot was a Dutch mathematician, the leading Dutch topologist for more than two decades following World War II. http://duckduckgo.com/c/Topologists
Full Alphabetical Index List of mathematical biographies indexed alphabetically. Full Alphabetical Index http://www.gap-system.org/~history/Indexes/Full_Alph.html
Abbe G. Edouard Lemaitre Encyclopedia Topics Reference.com Groot, Johannes De (Netherlands, 1914 1972) Gross, Benedict (USA, 1950 - ) Grossberg, Rami (Israel/USA, ? - ) Grossman, Alex (?, 1930 - ) Grossman, Edna (USA, ? http://www.reference.com/browse/abbe g. edouard lemaitre
Subjects We Know About - True Knowledge Protected by US patents 7,013,308 and 7,707,160. Other US and international patents pending. http://www.trueknowledge.com/subjects/J/598/
Jakub Majerski's Speedskating Database Arjen DE GROOT Johannes DE GROOT Leon DE GROOT Marco DE GROOT Martijn DE GROOT Martijn87 DE GROOT Rik DE GROOT Arne DE GROOTE Eric DE HAAN Jesse DE HAAN http://www.sskating.com/name_list.php?letter=D&lm=m
Librarium Of The Hague - Those Ancient Fields Studies Of 54 GROOT, Johannes, de. Palestijnsche masseben (opgerichte steenen) Academisch proefschrift Groningen, J. B. Wolters, 1913. Royal 8vo. Pp. 95. http://www.librarium.nl/static-list/those_ancient_fields.htm