edited by Robert E.C. Wildman
CRC press, 2007
Buku Teks
edited by Edward R. Farnworth
CRC Press, Taylor & Francis Group, 2008
Buku Referensi
Jacobs, Morris B.
Van Nostrand Reinhold, 1962
Buku Teks
Nadia Lenggo Geni
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2017
UI - Makalah dan Kertas Kerja
edited by Joop J. Hox, J. Kyle Roberts
Routledge, 2011
Buku Teks