Clements' main research was in phonology with a special focus on African languages. He is best known for his research in syllable theory, tone and feature theory which have contributed to the modern theory of sound patterning in spoken language. At the time of his death, his work was concerned with the principles underlying speech sound inventories across languages.
Clements, G. N. & S. J. Keyser, 1983. CV Phonology: a Generative Theory of the Syllable (Linguistic Inquiry Monograph 9), MIT Press, Cambridge, Ma.
Halle, Morris & G. N. Clements, 1983. Problem Book in Phonology. Cambridge, Ma.: MIT Press and Bradford Books.
Clements, G. N. & J. Goldsmith, eds., 1984. Autosegmental Studies in Bantu Tone. Berlin: Mouton de Gruyter
Other selected publications
Clements, G. N., 1985. "The Geometry of Phonological Features," Phonology Yearbook 2, 225-252
Clements, G. N., 1990. "The Role of the Sonority Cycle in Core Syllabification." In John Kingston & M. Beckman, eds., Papers in Laboratory Phonology I, Cambridge: Cambridge University Press, Cambridge, MA, pp. 283-333
Clements, G. N. & Elizabeth Hume, 1995. "The Internal Organization of Speech Sounds" In John Goldsmith, ed., Handbook of Phonological Theory. Oxford: Basil Blackwell, Oxford, pp. 245-306
Clements, G. N., 2003. "Feature Economy in Sound Systems", Phonology 20.3, pp. 287-333
Clements, G. N. & Annie Rialland, 2008. "Africa as a phonological area". In Bernd Heine & Derek Nurse, eds, A Linguistic Geography of Africa. Cambridge: Cambridge University Press, pp. 36-85.