@article{nielson-nanz-nielson:2011:modal, author = {Nielson, Flemming and Nanz, Sebastian and Nielson, Hanne Riis}, title = {Modal abstractions of concurrent behavior}, journal = {ACM Transactions on Computational Logic}, volume = {12}, number = {3}, year = {2011}, pages = {1--40}, urltopdf = http://se.inf.ethz.ch/people/nanz/publications/nielson-nanz-nielson_tocl11.pdf}