Session

http://stackoverflow.com/questions/3804209/what-are-sessions-how-do-they-work

http://www.webopedia.com/TERM/U/user_session.html

http://searchsoa.techtarget.com/definition/session

http://en.wikipedia.org/wiki/Session_(computer_science)

http://www.allaboutcookies.org/cookies/session-cookies-used-for.html

http://www.lassosoft.com/Tutorial-Understanding-Cookies-and-Sessions

http://php.about.com/od/learnphp/qt/session_cookie.htm

http://techterms.com/definition/session

http://www.computerhope.com/jargon/s/session.htm

http://www.webstepbook.com/supplements/slides/lecture25-cookies.shtml

http://docs.oracle.com/javaee/6/tutorial/doc/gipjg.html

http://www.business2community.com/seo/session-look-google-analytics-change-0863538