@Book{BVMC:636750, author = {Versor, Johannes}, author = {Francesco da Prato}, author = {Juan XXI, Papa}, title = {Expositio super Summulas Petri Hispani, una cum textu}, url = {https://www.cervantesvirtual.com/obra/expositio-super-summulas-petri-hispani-una-cum-textu-0} }