Getis, Arthur, author
Macmillan, 1985
Buku Teks
by William G. Moseley ... [and others]
Wiley Balckwell, 2014
Buku Teks
Knapp, Brian, author
Longman House, 1992
Buku Teks
edited by Gwen Bell
Hawaii University Press, 1976
Buku Teks
Treshow, Michael, author
McGraw-Hill, 1976
Buku Teks