Nagel, Michael C.
Oxford University Press, 2016
Buku Teks
Omrod, Jeanne Ellis
Pearson Education, Inc., 2009
Buku Teks
Bloom, Benyamin S.
McGraw-Hill, 1976
Buku Teks
National Training Laboratories Institute for Applied Behavioral Science
Institute for Applied Behavioral Science, 1968
Buku Teks
Lefrancois, Guy R.
Wadsworth, 2012
Buku Teks