Johnson, Glen M.
McGraw-Hill, 1999
Buku Teks
Whitehead, Randall
Rockport, 1998
Buku Teks
Szenasy, Susan S.
Running Press, 1986
Buku Referensi
Whitehead, Randall
Rockport Publishers, 1993
Buku Referensi
Nuckolls, James L.
John Wiley & Sons, 1983
Buku Teks