Controlled vocabularies allow an accurate and controlled approach in describing physical and digital assets (e.g., data). One of such controlled vocabulary is Psychology Variables. This controlled vocabulary is produced in Metadata 4 Machine (M4M) Workshop 20 (M4M.20 FAIRware Psychology), which is one of deliverables of FAIRware project funded by RoRi. sheet2rdf is used to build and serve Psychology Variables, while PURL is used to persist identifiers for the vocabulary, which resolve on BioPortal (Stanford's ontology service): http://purl.org/m4m20/variables/