[3235] Brenzinger, Matthias (1992) : Lexical retention in language shift: Yaaku/Mukogodo-Maasai and Elmolo/Elmolo-Samburu
[25411] Ehret, Christopher (2008) : Yaakuan and Eastern Cushitic: A Historical Linguistic Overview
[22578] Greenberg, Joseph Harold (1963) : The Mogogodo, a forgotten Cushitic people
[8365] Hayward, Richard J. (1978) : The Qawko dialects and Yaaku
[8489] Heine, Bernd (1974/75) : Notes on the Yaaku language (Kenya)
[13187] Mathenge, Gakuu (2002) : Unesco certifies Yaaku language and 30 others in EA dead
[25400] Takács, Gábor (Ed) (2008) : Semito-Hamitic festschrift for A.B. Dolgopolsky and H. Jungraithmayr