Zbigniew Suraj Piotr Grochowalski Lukasz Lew Discovering Patterns of Collaboration in Rough Set Research: Statistical and Graph-Theoretical Approach. 238-247 2011 RSKT https://doi.org/10.1007/978-3-642-24425-4_33 conf/rskt/2011 db/conf/rskt/rskt2011.html#SurajGL11