Hello I use the xml interface to list all publications that dont match a search criteria: /field[@name='keywords' and not (contains(text(),'alpha'))] but there are entries where the keywords field is missing. how can I include them (here "test-3") in the output? Thanks Michael -------------------------- \startbuffer[bib] @article{test-1, title = {Article One}, author = {A. Foo and X. Bar}, year = {2001}, keywords = {alpha}, } @book{test-2, title = {Book Two}, author = {B. Foo}, year = {2002}, keywords = {beta}, } @whatever{test-3, title = {Book Three}, author = {C. Foo}, year = {2003}, } \stopbuffer \usebtxdataset [database] [bib.buffer] \convertbtxdatasettoxml [database] \startxmlsetups btx:tag \hbox{\xmlatt{#1}{tag}} \stopxmlsetups \startxmlsetups btx:demo \xmlfilter {#1} { /bibtex /* /field[@name='keywords' and not (contains(text(),'alpha'))] /.. /command(btx:tag) } \stopxmlsetups \starttext \xmlsetup{btx:database}{btx:demo} \stoptext Michael Eidenbenz / Senior Researcher eidenbenz@arch.ethz.ch mailto:eidenbenz@arch.ethz.ch Phone +41 44 632 33 46 Chair of Architecture and Building Process ETH Zurich / Building HIB / Floor E / Room 33 Stefano-Franscini-Platz 1 / CH-8093 Zurich www.bauprozess.arch.ethz.ch http://www.bauprozess.arch.ethz.ch/ / ITA Institute of Technology in Architecture Faculty of Architecture / ETH Zurich www.ita.arch.ethz.ch http://www.ita.arch.ethz.ch/