C24 and C25 share the same three motets, but in C25 (from I-Mfd [4]) they surround a Mass and the order is M089-M090-M091, whereas C24 (from I-Mfd 3) is a “standalone” cycle, and the order is M090-M089-M091. There is no attribution in either book, nor in ANNALI 1885 (the Imperatrix gloriosa attributed to Gaffurius there at 169 is not M089 but M016). As for the catalogue BERWIN-HIRSCHFELD 1892, 91, it is unclear whether the Mass is included in the attribution to Gaffurius, or M089 only is intended. EITNER 1900-04, IV, 122 indicates, however, that the Mass is indeed a Missa [super] Imperatrix gloriosa; WARD 1986, 497 seems to accept the attribution and extends it to the other two motets, followed by Bonnie J. BLACKBURN, "Gaffurius, Franchinus," Grove Music Online. Oxford Music Online (Oxford University Press), http://www.oxfordmusiconline.com/subscriber/article/grove/music/10477.