Niel, C. B. (1932). "On the morphology and physiology of the purple and green sulphur bacteria". Archiv für Mikrobiologie. 3: 1–112. doi:10.1007/BF00454965. S2CID19597530.
Barker, H. A.; Robert E Hungate (1990). "Cornelis Bernardus van Niel, 1897-1985 : a biographical memoir". In National Academy of Sciences (ed.). Biographical Memoirs(PDF). Vol. 59. Washington, D.C.: National Academy Press. pp. 388–423. ISBN0309041988.
Niel, C. B. (1932). "On the morphology and physiology of the purple and green sulphur bacteria". Archiv für Mikrobiologie. 3: 1–112. doi:10.1007/BF00454965. S2CID19597530.
stanford.edu
www-marine.stanford.edu
Hopkins Marine Station. "History". Archived from the original on January 26, 2013. Retrieved January 11, 2013.
web.archive.org
Hopkins Marine Station. "History". Archived from the original on January 26, 2013. Retrieved January 11, 2013.