STUDI-GREGORIANI FOR THE HISTORY OF THE LIBERTAS-ECCELSIAE, VOL 13 - THE GREGORIAN REFORM AND EUROPE, PAPERS FROM THE INTERNATIONAL-CONFERENCE HELD IN SALERNO, MAY 20-25, 1985 - ITALIAN, GERMAN, FRENCH, SPANISH AND ENGLISH - STICKLER,AM, CAPITANI,O, FUHRMANN,H, MACCARRONE,M, SCHIEFFER,R, VOLPINI,R