1. BAKITA (Baraza la Kiswahili la Taifa). (2017). Kamusi Kuu ya Kiswahili.
2. Language Decline and Death in Africa
3. Beidelman, T. O. (1967). The matrilineal peoples of eastern Tanzania (Zaramo, Luguru, Kaguru, Ngulu). The International African Institute.
4. Beidelman, T. O. (1971). The Kaguru: A matrilineal people of East Africa. Holt, Rinehart and Winston, Inc.