APA (7th ed.) Citation

Bryden, J. R., & Hughes, D. G. (1969). An index of Gregorian chant. Harvard University Press.

Chicago Style (17th ed.) Citation

Bryden, John R., and David G. Hughes. An Index of Gregorian Chant. Cambridge: Harvard University Press, 1969.

MLA (8th ed.) Citation

Bryden, John R., and David G. Hughes. An Index of Gregorian Chant. Harvard University Press, 1969.