Easterbrook, Don J.
Prentice-Hall, 1999
Buku Teks SO
Easterbrook, Don J.
McGraw-Hill, 1969
Buku Teks SO
Gregory, Kenneth J.
Sage , 2010
Buku Teks SO
Bloom, Arthur L.
Prentice-Hall of India, 1979
Buku Teks
edited by David J. Nash and Sue J. McLaren
Blackwell, 2007
Buku Teks SO