APA (7th ed.) Citation

The notation of polyphonic music, 900-1600 / by Willi Apel.

Chicago Style (17th ed.) Citation

The Notation of Polyphonic Music, 900-1600 / by Willi Apel.

MLA (9th ed.) Citation

The Notation of Polyphonic Music, 900-1600 / by Willi Apel.

Warning: These citations may not always be 100% accurate.