Chapman, Paul G., 1952-
Harvester Wheatsheaf , 1993
Buku Teks
Gilbert, Sara D.
McGrw-Hill, Inc. , 1993
Buku Teks
Anderton, Charles H, author
Cambridge University Press, 2019
eBooks
Martin, Anne
Routledger Kegan Paul , 1958
Buku Teks
Nijkamp, Peter, author
North-Holland Publishing, 1977
Buku Teks