 His most important contributions include Four Centuries of Swahili Verses (1979), Swahili Islamic Poetry (1971), Epic Poetry in Swahili and other African Languages, (1983), A Survey of Swahili Islamic Epic Sagas (1999).He also resided at the University of Dar es Salaam where he became Secretary of the East African Swahili Committee as well as Editor of the Journal of the same committee, after the death of W.H.Whiteley, in the 1970s.