Armitage, P.
Blackwell Scientific Publication, 1985
Buku Teks
Malinvaud, Edmond
North Holland , 1987
Buku Teks
Grant, Eugene Lodewick
McGraw-Hill, 1996
Buku Teks
Andrews, Frank M.
University of Michigan, 1981
Buku Teks
McMillan Public Comp, 1987
Buku Teks