Luis M. Laita Eugenio Roanes-Lozano Luis de Ledesma Tomasa Calvo L. Gozález-Sotos A Computer Algebra Approach to Relational Systems Using Gröbner Bases. 124-133 2001 conf/RelMiCS/2001 RelMiCS http://link.springer.de/link/service/series/0558/bibs/2561/25610124.htm db/conf/RelMiCS/RelMiCS2001.html#LaitaRLCG01