A. N. Tucker 
Eastern Sudanic Languages [PDF ebook] 

Originally published in 1940 this book focusses on the three main groups of Eastern Sudanic languages, namely Moru-Madi, Bong-Baka-Bagirmi and Ndogo-Sere. The term ‘Eastern Sudanic Languages’ is used here primarily in a geographical sense: the dialects in the Southern Sudan form the eastern boundary of sudanic speech, where it borders on the Nilotic wedge which, in turn divides it from Hamitic speech. Despite being described because of their geographical position, the languages discussed in this book will be grouped linguistically under the names of their best known representative dialects. As well as providing some history of the Eastern Sudanic tribes, this book also contains sections on vocabulary and grammar.