Umeshwar Dayal Ming-Chien Shan Issues in Operation Flow Management for Long-Running Acivities. 41-44 1993 16 IEEE Data Eng. Bull. 2 DEBU/93JUN-CD.PDF db/journals/debu/debu16.html#DayalS93 http://sites.computer.org/debull/93JUN-CD.pdf conf/ride/AhmedADKLS93 conf/sigmod/DayalGHKS93 conf/vldb/DayalHL91 books/mk/Elmagarmid92 books/mk/GrayR93