Artikel Jurnal
Stiggins, Richard J., author
Prentice-Hall, 2001
Buku Teks
Napitupulu, Posma Prima, author
Fakultas Psikologi Universitas Indonesia, 2013
UI - Skripsi (Membership)
edited by Murray S. Klamkin
Society for Industrial and Applied Mathematics, 1995
eBooks
Richman, Fred, author
Brooks/Cole, 1967
Buku Teks