Carelse, Xavier F.
John Wiley & Sons, 1983
Buku Teks
by Christoph Stocker, Ingrid Davids; Karl Heinz Bonath, Wolfgang Hieber
Wiley Eastern, 1979
Buku Teks
Loughran, John
Sense, 2012
eBooks
Organisation for Economic Co-operation and Development. Development Centre., 1972
Buku Teks
Anderson, Curtis B., author
Kendall/Hunt, 1990
Buku Teks