APA (7th ed.) Citation

Apel, W. (1949). The notation of polyphonic music, 900-1600 (4th ed. rev. and with commentary.). Mediaeval Academy of America.

Chicago Style (17th ed.) Citation

Apel, Willi. The Notation of Polyphonic Music, 900-1600. 4th ed. rev. and with commentary. Cambridge: Mediaeval Academy of America, 1949.

MLA (8th ed.) Citation

Apel, Willi. The Notation of Polyphonic Music, 900-1600. 4th ed. rev. and with commentary. Mediaeval Academy of America, 1949.