Coba jelasin Catatan dari Johann Tetzel dong

Ludwig von Pastor, The History of the Popes, from the Close of the Middle Ages, Ralph Francis Kerr, ed., 1908, B. Herder, St. Louis, Volume 7, pp. 347–348.

The reformation in Germany, Henry Clay Vedder, 1914, Macmillon Company, p. 405.

D. Martini Lutheri, Opera Latina: Varii Argumenti, 1865, Henricus Schmidt, ed., Heyder and Zimmer, Frankfurt am Main & Erlangen, vol. 1, p. 300. (Reprinted: Nabu Press, 2010, ISBN 1-142-40551-6 ISBN 978-1-142-40551-9).