Lankester, Ted, author
Macmillan, 1994
Buku Referensi
Byrne, Monica, author
Oxford University Press, 1973
Buku Teks
edited by Abdel R. Omran ; participating Advisory Board, John C. Cassel ... [and others]
Springer, 1974
Buku Teks
edited by Kenneth Lee, Anne Mills
Oxford University Press, 1984
Buku Teks
Organisation for Economic Co-operation and Development. Development Centre., 1972
Buku Teks