I Fiamminghi IV: O admirabile commercium. Brumel, Regis, Mouton, Josquin. Cappella Pratensis - Rebecca Stewart, Ricercar 207572
M264, M265 and M268 have further concordances in F-PN Cons. Rés. F. 41 (for the foliation, see the records of the individual motets). Because of its particular nature, this source (in which the motets are inserted as handwritten additions between printed masses by Carpentras) is not listed among the Other sources of the present cycle (see http://www.diamm.ac.uk/sources/2375/#/).
See information on this cycle as part of The Josquin Research Project.
This motet possibly quotes pre-existing material, but it can not be linked to any Cantus prius factus with a corresponding text.
See also The Josquin Research Project.