Polsson, Ken (29 July 2009). "June–December 1988". Chronology of the Commodore 64 Computer. Archived from the original on 9 July 2008. Retrieved 12 May 2007.
museumofplay.org
"Risk". The Strong Museum. Retrieved 26 January 2022.
Polsson, Ken (29 July 2009). "June–December 1988". Chronology of the Commodore 64 Computer. Archived from the original on 9 July 2008. Retrieved 12 May 2007.