Muir, Robert
Henry Frowde, Hodder & Stoughton, 1921
Buku Teks
Markus, John, 1911-
McGraw-Hill, 1971
Buku Referensi
Leslie D. "Doc" Long, Clifford Gordon, Charles F. Peck, Jack R. Benjamin
McGraw-Hill, 1982
Buku Referensi
Hurlbut, Cornelius S.
John Wiley & Sons, 1977
Buku Teks
Browning, Carl H.
Oxford University Press, 1937
Buku Referensi