Walton, Thomas F.
John Wiley & Sons, 1976
Buku Teks
NCC Publications, 1984
Buku Referensi
Nichols, Elizabeth A., author
McGraw-Hill, 1982
Buku Teks
Halsall, Fred, author
Addison-Wesley, 1996
Buku Teks
edited by Mac E. Van Valkenburg and Wendy M. Midleton
Newnes, 2002
Buku Referensi