Franck van Breugel Babita Sharma James Worrell Approximating a Behavioural Pseudometric Without Discount for Probabilistic Systems. 123-137 2007 conf/fossacs/2007 FoSSaCS http://dx.doi.org/10.1007/978-3-540-71389-0_10 db/conf/fossacs/fossacs2007.html#BreugelSW07