Tornyay, Rheba de
John Wiley & Sons, 1987
Buku Teks SO
edited by Martha J. Bradshaw, Arlene J. Lowenstein
Jones and Bartlett, 2014
Buku Teks SO
Esler, William K
Contemporary Publishing, 1988
Buku Teks
Reilly, Dorothy E.
Jones and Bartlett , 1999
Buku Teks SO
edited by Susan M. Hincliff
Churchill livingstone , 1979
Buku Teks SO