@ARTICLE{agotnes:jal-10,
   AUTHOR = "Thomas {\AA}gotnes and Philippe Balbiani and Hans van Ditmarsch and Pablo Seban",
   TITLE = "Group Announcement Logic",
     JOURNAL = "Journal of Applied Logic",
   VOLUME = 8,
   NUMBER = 1,
   PAGES = "62--81",
   YEAR = 2010}