Gutik, O., & Popadiuk, O. (2023). On the semigroup $\boldsymbol{B}_{\omega}^{\mathscr{F}_n}$, which is generated by the family $\mathscr{F}_n$ of finite bounded intervals of $\omega$. Carpathian Mathematical Publications, 15(2), 331–355. https://doi.org/10.15330/cmp.15.2.331-355