Chapin, F. Stuart (Francis Stuart), 1916-
University of Illinois Press, 1979
Buku Teks
Chusnul Mar`iyah
1998
Artikel Jurnal
Kaiser, Edward John
University of Illinois Press, 1995
Buku Teks
Marsh, William M.
McGraw-Hill, 1978
Buku Teks
Barlowe, Raleigh
Prentice-Hall, 1961
Buku Teks