Giacomo Bonanno Klaus Nehring Common Belief with the Logic of Individual Belief. 49-52 2000 46 Math. Log. Q. 1 http://dx.doi.org/10.1002/(SICI)1521-3870(200001)46:1<49::AID-MALQ49>3.0.CO;2-R db/journals/mlq/mlq46.html#BonannoN00