Tammar Shrot Yonatan Aumann Sarit Kraus Easy and hard coalition resource game formation problems: a parameterized complexity analysis. 433-440 2009 AAMAS (1) http://doi.acm.org/10.1145/1558013.1558072 conf/atal/2009-1 db/conf/atal/aamas2009-1.html#ShrotAK09