Huy, Phan Trung, and Nguyễn Quý Khang. “Regular Omega-Languages and Finite Monoids Having Infinite Products”. <i>Journal of Computer Science and Cybernetics</i> 19, no. 2 (July 26, 2012): 180–186. Accessed February 26, 2026. https://jcc.vast.vn/jcc/article/view/1512.