Universitas Indonesia, 2003
Buku Teks
Quality management unit University of Sumatera Utara, 2010
Buku Teks
M.K. (Muhammad Kamil) Tadjudin, author
UI-Press, 1998
Buku Teks
Bernhard, Andrea, author
VS Research, 2012
eBooks
Lewis, Ralph G., author
St. Lucie Press, 1994
Buku Teks