by Christoph Stocker, Ingrid Davids; Karl Heinz Bonath, Wolfgang Hieber
Wiley Eastern, 1979
Buku Teks SO
Tillery, Bill W.
McGraw-Hill Higher Education, 2007
Buku Teks SO
Loughran, John
Sense, 2012
eBooks
Organisation for Economic Co-operation and Development. Development Centre., 1972
Buku Teks
Anderson, Curtis B.
Kendall/Hunt, 1990
Buku Teks