Wade, Rex A, author
Cambridge University Press, 2017
Buku Teks
Kowalski, Ronald
Routledge, 1997
Buku Teks
Moorehead, Alan, author
Harper and Brother, 1958
Buku Teks
Pushkarev, S. G. (Sergei Germanovich), 1888-1980, compiler
Yale University Press, 1970
Buku Referensi
Rogger, Hans, author
Longman, 1992
Buku Teks