I found the following website that that has full page of links for those interested in Bantu languages:
Among the resources it lists is my good friend’s master’s thesis:
Daniel J. Duke, Aka as a Contact Language: Sociolinguistic and Grammatical Evidence MA thesis in Linguistics (2001) at University of Texas at Arlington.
This thesis presents a discussion of the typological classification and origins of the languages spoken by Central African Pygmies. It focuses on Aka, the language of the Bayaka Pygmies in Central African Republic (C.A.R.) and Congo-Brazzaville. The Aka language is shown to have arisen out of language contact between pygmy hunter-gatherers and the village agriculturalists with whom they trade. Typologically, Aka is a mixed language, with a Bantu structure but having a significant lexical and grammatical substratum that appears to be the remnant of an ancient pygmy language. The current language use patterns of the Bayaka and their villager patrons in the Lobaye region of C.A.R. are documented in detail. These patterns are analyzed and the analysis is applied to shed light on what language contact situation would have given rise to Aka.
About the author: Daniel J. Duke, MA, is a missionary in Cameroon with Wycliffe Bible Translators. His current project is with the Kwasio people in Southwestern Cameroon. He is working on PhD thesis at University of Leiden.