Ricard Gavaldà Gábor Lugosi Thomas Zeugmann Sandra Zilles Algorithmic Learning Theory, 20th International Conference, ALT 2009, Porto, Portugal, October 3-5, 2009. Proceedings 5809 2009 http://dx.doi.org/10.1007/978-3-642-04414-4 978-3-642-04413-7 ALT Lecture Notes in Computer Science Springer db/conf/alt/alt2009.html