doi: 10.1098/rspa.2007.0090 , 155-176 464 2008 Proc. R. Soc. A Marco Di Francesco, Andrea Pascucci and Sergio Polidoro ultraparabolic equations The obstacle problem for a class of hypoelliptic References ml#ref-list-1 http://rspa.royalsocietypublishing.org/content/464/2089/155.full.ht This article cites 25 articles, 1 of which can be accessed free Subject collections (312 articles) applied mathematics Articles on similar topics can be found in the following collections Email alerting service here the box at the top right-hand corner of the article or click Receive free email alerts when new articles cite this article - sign up in http://rspa.royalsocietypublishing.org/subscriptions go to: Proc. R. Soc. A To subscribe to This journal is © 2008 The Royal Society on June 1, 2011 rspa.royalsocietypublishing.org Downloaded from