Georg Gottlob Nicola Leone Francesco Scarcello Hypertree Decompositions and Tractable Queries. 21-32 1999 PODS db/conf/pods/pods99.html#GottlobLS99 conf/pods/99 DiSC2_1/out/papers/pods/hypertreedecompgenif.pdf http://doi.acm.org/10.1145/303976.303979 db/conf/pods/GottlobLS99.html books/aw/AbiteboulHV95 journals/bit/Arnborg85 journals/jacm/BeeriFMY83 journals/siamcomp/BernsteinG81 journals/ai/Bibel88 journals/siamcomp/Bodlaender96 journals/jacm/ChandraKS81 conf/stoc/ChandraM77 conf/icdt/ChekuriR97 journals/acr/DAtriM86 ... journals/ai/DechterP89 journals/jacm/Fagin83 journals/tods/FaginMU82 journals/jacm/Freuder85 books/fm/GareyJ79 journals/tods/GoodmanS82 conf/focs/GottlobLS98 ... ... ... journals/siamcomp/Greibach73 journals/ai/GyssensJC94 conf/adbt/GyssensP82 journals/jacm/JeavonsCG97 ... conf/pods/KolaitisV98 books/cs/Maier83 conf/pods/PapadimitriouY97 conf/icde/Qian96 journals/jal/RobertsonS86 journals/jcss/Ruzzo80 journals/jacm/SkyumV85 conf/mfcs/Sudborough77 journals/siamcomp/TarjanY84 books/cs/Ullman89 conf/icdt/Ullman97 conf/stoc/Vardi82 conf/vldb/Yannakakis81 ...