2009-05-15 PAO(Procedure Access Object) http://books.google.co.jp/books?id=Nhv9J1W3NooC&pg=PA157&lpg=PA157&dq=PAO%E3%83%91%E3%82%BF%E3%83%BC%E3%83%B3&source=bl&ots=6FC4vefAEn&sig=BPap2aEjrLIM_U2dP1QcvMLAQhs&hl=ja&ei=5fYMSpqrFJiZkQWXqOCjBA&sa=X&oi=book_result&ct=result&resnum=3#PPA169,M1