title: minimization of tree pattern queries s amer-yahia , s cho , l lakshmanan , d srivastava. authors: nan. venue: sigmod conference. year: 2001.0
title: efficient algorithms for minimizing tree pattern queries proc . of the acm sigmod conf . on management of data ,. authors: s amer-yahia , s cho , l lakshmanan , d srivastava. venue: nan. year: nan