Kennedy, Richard
Macmillan Publishing Co. Inc, 1982
Buku Teks
Kirst-Ashman, Karen Kay, author
Cengage Learning , 2017
Buku Teks
Kirst, Ashman Karen Kay, author
Cengage Learning, 2013
Buku Teks
Jones, M.A.
George Allen& Unwin , 1983
Buku Teks
Trattner, Walter I., author
Free Press, 1984
Buku Teks