Derech, V. D. “Structure of a Munn Semigroup of Finite Rank Every Stable Order of Which Is Fundamental or Antifundamental”. Ukrains’kyi Matematychnyi Zhurnal 61, no. 1 (January 25, 2009): 52-60. Accessed April 26, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3000.