Fixed points of covering upper and lower approximation operators. - Ali Akbar Estaji; Mehdi Vatandoost; Rahimeh Pourkhandani (Soft Comput., 2019)

A generalized modal logic in causal structures. - Mehdi Vatandoost; Ali Akbar Estaji; Rahimeh Pourkhandani (Theor. Comput. Sci., 2019)