Daniel Schwab, Emil. “The Bicyclic Semigroup As the Quotient Inverse Semigroup by Any Gauge Inverse Submonoid”. Journal of Algebra Combinatorics Discrete Structures and Applications 9, no. 2 (May 13, 2022): 123–131. Accessed September 12, 2026. https://jacodesmath.com/index.php/jacodesmath/article/view/226.