Artikel Jurnal
Tanham, George K., author
Ferderick A. Praeger, 1966
Buku Teks
edited by Andreas W. Daum, Lloyd C. Gardner, Wilfried Mausbach
Cambridge University Presss, 2003
Buku Teks
Logevall, Fredrik, 1963-, author
Random House Trade Paperbacks, 2012
Buku Teks
Appy, Christian G., author
Penguin, 2016
Buku Teks