Kehr, E. A. (1956). Vatican: The stamps and description of their designs and background prepared especially for stamp collectors. The Washington Press.
Chicago-Zitierstil (17. Ausg.)Kehr, Ernest A. Vatican: The Stamps and Description of Their Designs and Background Prepared Especially for Stamp Collectors. Newark, New Jersey: The Washington Press, 1956.
MLA-Zitierstil (8. Ausg.)Kehr, Ernest A. Vatican: The Stamps and Description of Their Designs and Background Prepared Especially for Stamp Collectors. The Washington Press, 1956.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.