Madden, Joseph W.
St. Paul Minn, 1931
Buku Teks
Kintner, Earl W.
Macmillan Publishing Co.Inc., 1973
Buku Teks
Oppenheim, L., author
Longmas, 1967
Buku Teks
Oppenheim, L., author
Longmas, Green , 1920
Buku Teks
Oppenheim, L., author
Longmas, Green , 1947
Buku Teks