J.  Köhler, Bwong, B. A., Schick, S., Veith, M., and Lötters, S., ?A new species of arboreal Leptopelis (Anura : Arthroleptidae) from the forests of western Kenya?, Herpetological Journal, vol. 16, pp. 183-189, 2006.

J.  Köhler, Scheelke, K., Schick, S., Veith, M., and Lötters, S., ?Contribution to the taxonomy of hyperoliid frogs (Amphibia: Anura: Hyperoliidae): advertisement calls of twelve species from East and Central Africa?, African Zoology, vol. 40, pp. 127-142, 2005.

J.  Köhler and Güsten, R., ?Herpetological type specimens in the natural history collections of the museums in Darmstadt and Wiesbaden, Germany?, Spixiana, vol. 30, pp. 275-288, 2007.

J.  Köhler, ?The identity of Hylambates rufus aubryioides Andersson, 1907 (Anura: Arthroleptidae) from Cameroon?, Copeia, vol. 2009, pp. 57-61, 2009.