@Article{,
title = {A survey of some recent developments in differential topology},
journal = {Bulletin of the American Mathematical Society},
author = {Smale, Stephen},
year = {1963},
volume = {69},
pages = {131{\textendash}145},
url = {http://www.ams.org/journals/bull/1963-69-02/S0002-9904-1963-10901-5}
}