Translation: The voicing of the Introitus is reduced to STB , and the Tractus is voiced SA.
Translation: Missa Prolationum composed by Johannes Ockeghem. 1410-1497. Naxos Classics. Choral.
Translation: 1410-1497. Edited by Darvas. For SMezATBarB Choir a cappella. Sheet Music. Published by Edition Kunzelmann. PE.OCT10135.