Niehaus, F. J. (2001). Karl's diary: Blessed Karl Leisner: in his own words. Schoenstatt Fathers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Niehaus, Fr Jonathan. Karl's Diary: Blessed Karl Leisner: In His Own Words. Waukesha, WI: Schoenstatt Fathers, 2001.
Παραπομπή σε μορφή MLA (8th εκδ.)Niehaus, Fr Jonathan. Karl's Diary: Blessed Karl Leisner: In His Own Words. Schoenstatt Fathers, 2001.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.