http://www.mansioningles.com/gram41.htm
http://www.mailxmail.com/curso-mas-completo-ingles/unidad-6-futuro-idiomatico-futuro-simple-futuro-continuo
http://es.wikibooks.org/wiki/Ingl%C3%A9s/Gram%C3%A1tica/El_tiempo_futuro
http://www.cedmm.org/ingles2/uni1.htm
http://www.englishgrammarsecrets.com/goingtofuture/exercise4.html
http://www.englisch-hilfen.de/en/exercises/tenses/will_going_to_future.htm