Stright, Barbara R.
J.B. Lippincott, 1996
Buku Teks SO
Addison-Wesley , 1988
Buku Teks SO
Sally B. Olds, Marcia L. London, Patricia A. Wieland Ladewig, Michele R. Davidson
Pearson Education, 2004
Buku Referensi
Reeder, Sharon J.
J.B. Lippincott, 1997
Buku Teks SO
Reeder, Sharon J.
J.B. Lippincott, 1997
Buku Teks SO