Wonderling, David
Open University Press, 2005
Buku Teks SO
Kobelt, Gisela
Office of Health Economics, 2002
Buku Teks SO
Sorkin, Alan L.
Massachusetts Lexington Books, 1984
Buku Teks SO
McLean, Robert A.
Delmar, 1997
Buku Teks
McLean, Robert A.
Delmar, 2003
Buku Teks