@article {16782,
	title = {Using differential technlques to efficiently support transaction time},
	journal = {The VLDB JournalVLDB Journal},
	volume = {2},
	year = {1993},
	month = {1993/01//},
	pages = {75 - 111},
	isbn = {1066-8888},
	doi = {10.1007/BF01231799},
	url = {http://dl.acm.org/citation.cfm?id=615162},
	author = {Jensen,Christian S. and Mark,Leo and Roussopoulos, Nick and Sells,Timos}
}
