Links
Chance Wiki:
http://www.causeweb.org/wiki/chance/index.php/Main_Page
CAUSEweb,org:
http://www.causeweb.org/cwis/index.php?P=BrowseResources&ParentId=78
Chapter 18:
The Long Run and Expected Value (P.B. Stark, UC Berkeley)
http://www.stat.berkeley.edu/~stark/SticiGui/Text/expectation.htm