Defensorium obedientiae apostolicae et alia documenta /
Biel, Gabriel.
Oberman, Heiko Augustinus.
Zerfoss, Daniel E.
Courtenay, William J.
Cambridge (Mass.) :  Belknap P. of Havard U.P. ; London : Oxford U.P.,
1968.
Parallel Latin text, English translation.
Includes bibliographical references and index.