http://www.paragoncode.com/shop/vacuum_pump/ (http://www.paragoncode.com/shop/vacuum_pump/)
http://pages.sprint.ca/wmanson/files/vacbag.html (http://pages.sprint.ca/wmanson/files/vacbag.html)
http://www.berkut13.com/sucker.htm (http://www.berkut13.com/sucker.htm)
http://www.pupman.com/listarchives/1999/September/msg00050.html (http://www.pupman.com/listarchives/1999/September/msg00050.html)