Cindy Eisner Dana Fisman John Havlicek Anthony McIsaac David Van Campenhout The Definition of a Temporal Clock Operator. 857-870 2003 conf/icalp/2003 ICALP http://link.springer.de/link/service/series/0558/bibs/2719/27190857.htm db/conf/icalp/icalp2003.html#EisnerFHMC03