Dickinson, Robert E.
Routledge & Kegan Paul Ltd , 1956
Buku Teks
Mumford, Lewis, author
Harcourt , 1961
Buku Teks
Dickinson, Robert E.
Kegan Paul, Trench, Trubner, 1947
Buku Teks
edited by Robin Middleton
MIT Press, 1996
Buku Teks
Clark, David, 1946-, author
Routledge, 1996
Buku Teks