Found 1 pathways with zero (PubMed) references
* [http://classic.wikipathways.org/instance/WP218_r117337](http://classic.wikipathways.org/instance/WP218_r117337) 'Serine and glycine biosynthesis' in Saccharomyces cerevisiae has zero references;
More details at https://www.wikipathways.org/WikiPathwaysCurator/ReferencesTests/atLeastOneReference