Happach, P. O. Archivmaterialien zu Paul Otto Happach, 1878-1962.
Chicago Style (17th ed.) CitationHappach, Paul Otto. Archivmaterialien Zu Paul Otto Happach, 1878-1962.
MLA引文Happach, Paul Otto. Archivmaterialien Zu Paul Otto Happach, 1878-1962.
警告:這些引文格式不一定是100%准確.