Gould, W.T.S., author
John Wiley, Longman Scientific, 1993
Buku Teks
edited by Keith Watson
Croom Helm, 1982
Buku Teks
Valkenier, Elizabeth Kridl, author
Frederick A. Praeger, 1983
Buku Teks
Asuncion Lopez-Varela, editor
Common Ground, 2014
Buku Teks
Meller, Helen, author
John Wiley & Sons, 2001
Buku Teks