Williamson, G. (2012). U Boot Waffe Pasukan Kapal Selam Jerman Perang Dunia II. Kepustakaan Populer Gramedia.
Chicago Style (17th ed.) CitationWilliamson, Gordon. U Boot Waffe Pasukan Kapal Selam Jerman Perang Dunia II. Kepustakaan Populer Gramedia, 2012.
MLA (8th ed.) CitationWilliamson, Gordon. U Boot Waffe Pasukan Kapal Selam Jerman Perang Dunia II. Kepustakaan Populer Gramedia, 2012.
Warning: These citations may not always be 100% accurate.