@article{journals/tods/OzsoyogluOM87,
title = {Extending Relational Algebra and Relational Calculus with Set-Valued Attributes and Aggregate Functions.},
author = {Gultekin Özsoyoglu and Z. Meral Özsoyoglu and Victor Matos},
journal = {ACM Trans. Database Syst.},
number = {4},
pages = {566-592},
url = {http://dblp.uni-trier.de/db/journals/tods/tods12.html#OzsoyogluOM87},
volume = {12},
year = {1987},
description = {dblp},
ee = {db/journals/tods/OzsoyogluOM87.html}, date = {2006-04-03}, cite = {...}, cdrom = {TODS12/P566.PDF},
keywords = {algebra database folksonomy relational }
}
::