https://books.google.com.br/books?id=NOuoAwAAQBAJ&pg=PA37&lpg=PA37&dq=murillo+de+aragao+%22mit+press%22&source=bl&ots=0BVCAJxzcN&sig=ACfU3U2p3_8pArDcmiUBWNjdBStpzKAYJw&hl=en&sa=X&ved=2ahUKEwjz58jdgb6HAxV_FbkGHSm8DqQ4ChDoAXoECB0QAw#v=onepage&q=murillo%20de%20aragao%20%22mit%20press%22&f=false