I already knewe they work, because I have added two inches using the Jes-extender, but if there is still anyone who is skeptical and needs another source to confirm it, read this:
http://www.ingentaconnect.com/searc...8&year_to=2008&database=1&pageSize=20&index=6
http://www.ingentaconnect.com/searc...8&year_to=2008&database=1&pageSize=20&index=6