B. Pascal, N. Pierre, and P. Pierre, Lexique comparatif historique des langues sara-bongo-baguirmiennes

N. Pierre, Les parlers gula (Centrafrique, Soudan, Tchad), Grammaire et lexique, 1999.

P. Prashant, The compound verb in Marathi: definitional issues and criteria for identification, Kobe Papers in Linguistics, pp.94-1111, 2001.

S. Stefano, Brief Grammar Outlines of the Yulu and Kara languages, 1970.