Team S. A Simple Proof of Caristi’s Fixed Point Theorem without Using Zorn’s Lemma and Transfinite Induction: Wei-Shih Du. Thai J Math [Internet]. 2016 Aug. 1 [cited 2024 May 1];14(2):259-64. Available from: https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/595