@article{Thi_1987, title={Strong dependencies and s-semilattices}, volume={8}, url={https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3332}, number={2}, journal={Acta Cybernetica}, author={Thi, Vu Duc}, year={1987}, month={Jan.}, pages={195-202} }