Gaya APA

Hess, C, R, O. (1969). The tract on Holy Orders in the Summa of Roland of Cremona. Pars dissertationis Angelicum. . Romae: Catholic Book Agency.

Gaya MLA

Hess, Charles, R.,, O.P.. "The tract on Holy Orders in the Summa of Roland of Cremona. Pars dissertationis Angelicum. ". Romae: Catholic Book Agency, 1969. Buku.