McNeill, Patrick, author
Routledge, 1999
Buku Teks
Polit, Denise F., author
Lippincott, 1999
Buku Teks
Blaxter, Loraine, author
Open University Press , 1996
Buku Teks
Saunders, Mark, author
Prentice-Hall, 2003
Buku Teks
White, Theresa L., author
Wadsworth and Cengage Learning, 2013
Buku Teks