Institute for Scientific co-coperation, [date of publication not identified]
Majalah, Jurnal, Buletin
Digital Equipment Corporation, 1984
Buku Referensi
Knowles, Malcolm S., author
Routledge, 2015
Buku Teks
Tooley, James, author
Continuum Studies Education Policy, 2000
Buku Teks
Artikel Jurnal