DerechV. D. “Structure of a Finite Commutative Inverse Semigroup and a Finite Bundle for Which the Inverse Monoid of Local Automorphisms Is Permutable”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 63, no. 9, Sept. 2011, pp. 1218-26, https://umj.imath.kiev.ua/index.php/umj/article/view/2799.