Walker, Edward Everett, 1900-1974
Charles Scribner's Sons, 1943
Buku Teks
Boyd, Anne Morris
H.W. Wilson, 1949
Buku Teks
Zink, Harold
Van Nostrand , 1963
Buku Teks
The America University, [date of publication not identified]
Buku Teks
MD : Bernan Press, 2004
Buku Teks