Wiley-VCH, 2004
Buku Teks
Taylor and Francis, 1997
Buku Teks
edited by Martin Fransman, Gerd Junne and Annemieke Roobeek
Blackwell, 1995
Buku Teks
Primrose, S.B., author
Blackwell, 1991
Buku Teks
Redden, Kenneth R., author
The Michie Company, 1980
Buku Referensi