"Closing the crawl"(PDF). Builder magazine Oct 2005 (reproduced by advancedenergy.org). Archived from the original(PDF) on 10 February 2009. Retrieved 3 July 2009.
"Closing the crawl"(PDF). Builder magazine Oct 2005 (reproduced by advancedenergy.org). Archived from the original(PDF) on 10 February 2009. Retrieved 3 July 2009.