http://books.google.com/books?id=sfp-OzoU6X4C&amp;pg=PA453&amp;lpg=PA453&amp;dq=internal+os+funneling&amp;source=bl&amp;ots=out9U_Il7L&amp;sig=ox7MNSnknYT4nIvWnl9S4Jy7hmg&amp;hl=en&amp;ei=KPwTSrauJM6W_AanycilDw&amp;sa=X&amp;oi=book_result&amp;ct=result&amp;resnum=6#PPA455,M1