Marrelli, Tina M., author
Elsevier Mosby, 2012
Buku Referensi
edited by Coleen K. Withgott, Austin G. Anderson
Merriam-Webster, 1981
Buku Referensi
editor, Jerry Mintz
Macmillan, 1994
Buku Referensi
De Vries, Mary Ann, author
Prentice-Hall, 1991
Buku Referensi
Lee Harrison, editor in chief
McGraw-Hill, 1995
Buku Referensi