Hoyt, Robert S.
Harcourt, Brace & World, 1966
Buku Teks
Kirchner, Walther
Barnes & Noble. INC, 1968
Buku Teks
Southern, R.W. (Richard William), 1912-2001
Cresset Librar, 1967
Buku Teks
general editor, H.R. Loyn
Thames and Hudson, 1991
Buku Referensi
editor, William Chester Jordan
Charles Scribner's Sons, 1996
Buku Referensi