Found 1 pathways with zero (PubMed) references
* [http://classic.wikipathways.org/instance/WP256_r125521](http://classic.wikipathways.org/instance/WP256_r125521) 'Cysteine biosynthesis from homoserine' in Saccharomyces cerevisiae has zero references;
More details at https://www.wikipathways.org/WikiPathwaysCurator/ReferencesTests/atLeastOneReference