References continued:
Wolcott, Barbara, 1999. Sun Worship: solar power is gaining more backers in the commercial market, as new technology and less intrusive design enhance it’s appeal. Mechanical Engineering-CIME 121:62-65.
Solar Electric Power Association (SEPA)(b), 2001. Monthly tabular summary for: Green Bay WI. Retrieved 29 November 2001 from http://66.92.90.179/upvg_sites_page.htm.