Herman the Cripple - Catholic Online Schlager, Patricius, "Hermann Contractus," The Catholic Encyclopedia (New York: Robert Appleton, 1910), retrieved May 13, 2014, from New Advent.
Herman the Cripple - Catholic Online ^ Schlager, Patricius, "Hermann Contractus," The Catholic Encyclopedia (New York: Robert Appleton, 1910), retrieved ngày 13 tháng 5 năm 2014, from New Advent.