1.
LI M, SUGAWA T. Some extensions of the Open Door Lemma. Stud. Univ. Babeş-Bolyai Math. [Internet]. 2015 Sep. 30 [cited 2025 Feb. 5];60(3):421-30. Available from: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5793