title: sideway value algebra for object-relational databases 2002. authors: g жzsoyoglu , a al-hamdani , i altingіvde , s жzel , ж ulusoy , z жzsoyoglu. venue: vldb. year: nan
title: four valued logic for relational database systems gh gessert sigmod record , 1990.0. authors: nan. venue: nan. year: nan