Akpan, Ekaete Evangel. 2006. "Assimilatory Processes in Ibibio Child Phonology." In Selected proceedings of the 36th annual conference on African linguistics: shifting the center of Africanism in language politics and economic globalization, edited by Olaoba F. Arasanyin and Michael A. Pemberton. 27-36. Cascadilla Proceedings Project.
Aklilu, Yilma, Ralph Siebert and Kati Siebert. 2002. "Sociolinguistic Survey Report of the Omotic Languages Sheko and Yem." 26. SIL International.
Aklilu, Yilma, Ralph Siebert and Kati Siebert. 1993. "Survey of the Omotic Languages “Sheko” and “Yem”." In SLLE (Survey of little-known languages of Ethiopia) linguistic reports, 10: 1-26.
Aklilu, Yilma and Ralph Siebert. 2002. "Sociolinguistic Survey Report of the Chara, Dime, Melo and Nayi Languages of Ethiopia." pt. 1: 11. SIL International.
Aklilu, Yilma and Ralph Siebert. 1995. "Survey of Chara, Dime, Melo and Nayi." In SLLE (Survey of little-known languages of Ethiopia) linguistic reports, 25: 2-7.