Karapinar, ErdalNguyen Van LuongMathematics2024-07-052024-07-0520120898-12211873-766810.1016/j.camwa.2012.02.0612-s2.0-84865658898https://doi.org/10.1016/j.camwa.2012.02.061https://hdl.handle.net/20.500.14411/333KARAPINAR, ERDAL/0000-0002-6798-3254; Nguyen, Luong/0000-0002-5784-5552The notion of coupled fixed point is introduced by Gnana-Bhaskar and Lakshmikantham. Very recently, the concept of tripled fixed point was introduced by Berinde and Borcut. In this manuscript, a quadruple fixed point is considered and some new related fixed point theorems are obtained. We also give some examples to illustrate our results. (c) 2012 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/openAccessFixed point theoremsNonlinear contractionPartially orderedQuadruple fixed pointArticleQ164618391848WOS:00030924810002750