Rottland, Franz and Duncan Okoth okombo. 1992. "Language Shift Among the Suba of Kenya." In Language death: factual and theoretical explorations with special reference to East Africa, edited by Matthias Brenzinger. 273-283. Mouton de Gruyter.

Franz Rottland and Angelika Jakobi. 1991. "Loan Word Evidence From the Nuba Mountains: Kordofan Nubian and the Nyimang Group." In Ägypten im Afro-orientalischen Kontext. Aufsätze zur Archäologie, Geschichte und Sprache eines unbegrenzten Raumes: Gedenkschrift Peter Behrens, edited by Daniela Mendel and Ulrike Claudi. 249-269. Inst. für Afrikanistik, Univ. zu Köln.

Rottland, Franz. 1982. "Die Südnilotischen Sprachen: Beschreibung, Vergleichung Und Rekonstruktion." 563. Dietrich Reimer Verlag.

Rongier, Jacques. 1996. "Aperçu Sur Le Moyobe." In Cahiers voltaïques / Gur papers, 1: 115-145.

Rombi, Marie-Françoise and Jacqueline Mauricette Christiane Thomas. 2006. "Un Continuum Prédicatif: Le Cas Du Gbanzili (République Centrafricaine)." 384. Ed. Peeters.

James S. Roberts. 2001. "Phonological Features of the Central Chadic Languages." In Research mate in African linguistics (focus on Cameroon): a fieldworker’s tool for deciphering the stories Cameroonian languages have to tell, in honor of Professor Larry M. Hyman, edited by Ngessimo M. Mutaka and Beban Sammy Chumbow. 93-118. Rüdiger Köppe Verlag.

Paris W. Reidhead. 1947. "Note On the Ganza Language: a Preliminary Descriptive Analysis." Sudan Interior Mission (SIM).

Raymond, W.D. 1936. "Native Materia Medica." In Tanganyika notes and records, 2: 50-54.

Pascale Piron. Eléments De Description Du Kota, Langue Bantoue Du Gabon, B.25. Master thesis, Univ. Libre de Bruxelles, 1990.

Andrew M. Persson. A Dialect Study of the Jur Beli Cluster. PhD thesis, University of Khartoum, 1979.