K. Göschka:
"The Hypertext Transfer Protocol";
in: "The Industrial Information Technology Handbook", issued by: Zurawski, R.; CRC Press, Boca Raton, Florida, USA, 2005, ISBN: 0-8493-1985-4, 30-1 - 30-23.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04968576