Tomasowa, Francien Herlen, author
Lembaga Penerbitan Fakultas Pertanian Universitas Brawijaya, 2005
Buku Teks
edited by Michael S. Lewis-Beck
Sage, 1993
Buku Referensi
Michael S. Lewis-Beck, editor
Sage Publications, 1993
Buku Referensi
Blum, Julius R., author
W.B. Saunders, 1972
Buku Teks
Levin, Richard I., author
Prentice-Hall, 1998
Buku Teks