Abhishek Swaroop Awadhesh Kumar Singh A Hierarchical Approach to Handle Group Mutual Exclusion Problem in Distributed Systems. 462-467 2009 ICDCN https://doi.org/10.1007/978-3-540-92295-7_56 conf/icdcn/2009 db/conf/icdcn/icdcn2009.html#SwaroopS09