Shier, Douglas R., author
Oxford University Press, 1991
Buku Teks
Neufelder, Ann Marie, author
Marcel Dekker, 1993
Buku Teks
Smith, C.S., author
Pitman, 1969
Buku Teks
Colbourn, Charles J., author
Oxford University Press, 1987
Buku Teks
Neubeck, Ken, author
Pearson Prentice Hall, 2004
Buku Teks