@article { RZP12a, title = {Wellformedness Properties in Euler Diagrams: Which Should be Used?}, journal = {IEEE Transactions on Visualization and Computer Graphics}, month = {Jul}, number = {7}, pages = {1089-1100}, url = {http://ieeexplore.ieee.org/xpl/freeabs\_all.jsp?arnumber=5999665}, doi = {10.1109/TVCG.2011.143}, year = {2012}, author = {Rodgers, Peter and Zhang, Leishi and Purchase, Helen} }