Williamson, Samuel J.
Addison-Wesley, 1973
Buku Teks
Davenport, S.J.
Washington, DC: United States Department of the Interior, 1954
Buku Teks
De Nevers, Noel, 1932-, author
McGraw-Hill, 1995
Buku Teks
Colbeck, I. (Ian), author
Elsevier, 1994
Buku Teks
Devinny, Joseph S., author
Lewis Publishers, 1999
Buku Teks