Cos, F. Salvadó y. 1891. "Colección De Apuntes Preliminares Sobre La Lengua Benga: Ó Sea, Intrucción a Una Gramática De Este Idioma." Madrid: A. Pérez Dubrull.

Sasse, Hans-Jürgen. 1974. "Notes On the Structure of Galab." In Bulletin of the School of Oriental and African Studies, 37 , no. 2: 407-438.

Rupp, S. I, You, We, They: Forests of Identity in Southeastern Cameroon. PhD thesis, New Haven: Yale University, 2001.

Rowlands, E. C. 1962. "Notes On Some Class Languages of Northern Nigeria." In African Language Studies, 3: 71-83.

Rottland, Franz and Rainer Vossen. 1977. "Grundlagen Für Eine Klärung Des Dorobo-Problems." In Zur Sprachgeschichte und Ethnohistorie in Afrika: neue Beiträge afrikanistischer Forschungen, edited by Wilhelm J. G. Möhlig et al.. 213-238. Berlin: Dietrich Reimer.

Rottland, Franz. 1990. "A Sketch of Shinasha Morphology." In Omotic Language Studies, edited by Richard J. Hayward. 185-209. School of Oriental and African Studies.

Rood, N. 1958. "Ngombe-Nederlands-Frans Woordenboek/Dictionnaire Ngombe-néerlandais-français." 21: Tervuren: Comissie voor Afrikaanse Taalkunde/Commission de Linguistique Africaine.

Rombi, Marie-Françoise. 1983. "Le Shimaore: Première Approche D'un Parler De La Langue Comorienne (^ıle De Mayotte, Comores)." 3: Paris: SELAF.

Rogers, Henry E. The Phonology and Morphology of Sherbro. PhD thesis, Yale University, 1967.

Roberts, D. F. 1957. "Contribuzione Alla Etnologia Dei "Pre-Niloti": I Mabaan a Paragone Der Niloti." In Rivista di Antropologia, 44: 317-324.