(A) Leopold Buch (1774-1853; http://www.diariodeavisos.com/2015/12/bicentenario-estancia-leopold-von-buch/),
(B) Rudolf Carnall (1804-1874; http://www.montes.pl/montes/index.php?option=com_content&task=view&id=246&Itemid=650),
(C) Carl Ferdinand Roemer (1818-1891; http://www.bibliotekacyfrowa.pl/dlibra/publication/33271/edition/37739/content?ref=desc)