Talal Rahwan Tomasz P. Michalak Nicholas R. Jennings Michael Wooldridge Peter McBurney Coalition Structure Generation in Multi-Agent Systems with Positive and Negative Externalities. 257-263 2009 IJCAI http://ijcai.org/papers09/Papers/IJCAI09-052.pdf conf/ijcai/2009 db/conf/ijcai/ijcai2009.html#RahwanMJWM09