Masson, VeNeta
Springer Publ ., 1981
Buku Teks
edited by David N. Balaam and Michael J. Carey
Allanheld, Osmun, 1981
Buku Teks
University of Pittsburgh Press, 1980
Buku Teks
John Wiley & Sons, 1985
Buku Teks
Castells, Manuel, author
Macmillan, 1978
Buku Teks