"Naegeli [Nägeli], Carl Wilhelm von,"
Max Planck Institute for the History of Science, Berlin, http://vlp.mpiwg-berlin.mpg.de/people/data?id=per346 (accessed 03/30/2015) "Karl Wilhelm von Nägeli." Encyclopaedia Britannica. Encyclopaedia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2015. Web. 30 Mar. 2015. <http://academic.eb.com/EBchecked/topic/401656/Karl-Wilhelm-von-Nageli>.