pengantar, Taufik Abdullah
Pusat Data dan Analisa TEMPO, 2002
Buku Teks
Milne, R.S.
Federal Publications, 1977
Buku Teks
Harper and Brothers, 1959
Buku Teks
Mayer, JP
Faber and Faber, 1945
Buku Teks
Koestenbaum, Peter
Jossey-Bass Publishers, 1991
Buku Teks