http://ibsconsult.wordpress.com/2008/01/31/qu%E1%BA%A3n-tr%E1%BB%8B-chi%E1%BA %BFn-l%C6%B0%E1%BB%A3c-phan-tich-moi-tr%C6%B0%E1%BB%9Dng-kinh-doanh/