Barnett, A. Doak (Arthur Doak), author
Frederick A. Praeger, 1965
Buku Teks
Gale, George Stafford, author
Allen & Unwin, 1955
Buku Teks
Payne, Robert
William Heinemann, 1947
Buku Teks
Moraes, Francis Robert
Macmillan, 1953
Buku Teks
Hevi, Immanuel John
Frederick A. Praeger, 1963
Buku Teks