Stein, Lincoln D.
Official guide to programming with CGI.pm
Wiley, 1998
 Buku Teks
Oehler, Karsten
IBM Cognos TM1 : the official guide
McGraw-Hill, 2012
 Buku Teks
Anderson, Chris
TED talks: the official TED guide to public speaking
Headline Publishing Group, 2016
 Buku Teks
Skrob, Robert
Official get rich guide to information marketing
Entrepreneur Press, 2011
 Buku Teks
Guide to official statistics / Central Statistical Office
Her Majesty's Stationery Office, 1986
 Buku Referensi