Monica Wilson 
Communal Rituals of the Nyakyusa [PDF ebook] 

Originally published in 1959, this book includes detailed accounts of Nyakyusa traditions of origin, osmology and moral values, often in direct quotations from informants, while part of the book is devoted to a description of Christian missions, the growth of African churches and the conflict between pagan and Christian ethics and practices. The analysis of the effects of cchanges in the social and economic structure on the one hand, and religious beliefs and practices on the other, makes this a study of enduring relevance.