A variety theorem for relational universal algebraNester, Chad MitchellRelational and Algebraic Methods in Computer Science : 19th International Conference, RAMiCS 2021, Marseille, France, November 2–5, 2021 : proceedings2021 / p. 362–377 https://doi.org/10.1007/978-3-030-88701-8_22 Conference Proceedings at Scopus Article at Scopus Conference Proceedings at WOS Article at WOS