Billings, Diane M.
[publisher not identified], [year of publication not identified]
Buku Teks
Tornyay, Rheba de
John Wiley & Sons, 1982
Buku Teks
Reilly, Dorothy E.
Jones and Bartlett , 1999
Buku Teks
edited by Susan M. Hincliff
Churchill livingstone , 1979
Buku Teks
Pohl, Margaret L.
WM.C. Brown , 1978
Buku Teks