Systems of functional equations and generalizations of certain functions Symon Serbenyuk OriginalPaper 28 July 2021 Pages: 801 - 820
On symmetrized stochastic convexity and the inequalities of Hermite–Hadamard type Wasim Ul HaqDawid Kotrys OriginalPaper 01 July 2021 Pages: 821 - 828
On the Hyers–Ulam stability of certain nonautonomous and nonlinear difference equations Davor Dragičević OriginalPaper 15 January 2021 Pages: 829 - 840
Ternary mappings of triangular algebras Dolores Martín BarqueroCándido Martín GonzálezMorgan Vandeyar OriginalPaper 15 March 2021 Pages: 841 - 865
Orthogonality preserving property for pairs of operators on Hilbert \(C^*\)-modules Michael FrankMohammad Sal MoslehianAli Zamani ReviewPaper 16 March 2021 Pages: 867 - 887
A Birkhoff-James cosine function for normed linear spaces Vasiliki PanagakouPanayiotis PsarrakosNikos Yannakakis OriginalPaper 06 March 2021 Pages: 889 - 914
Numerical semigroups bounded by the translation of a plane monoid M. A. Moreno-FríasJ. C. Rosales OriginalPaper Open access 09 August 2021 Pages: 915 - 929
The conditional distributivity condition for T-uninorms revisited Wenwen ZongYong Su OriginalPaper 02 January 2021 Pages: 931 - 939
Generalization of Heron’s and Brahmagupta’s equalities to any cyclic polygon Paolo DulioEnrico Laeng OriginalPaper Open access 28 January 2021 Pages: 941 - 952
Homogeneity of isosceles orthogonality, transitivity of the norm, and characterizations of inner product spaces Senlin WuYixia HeChan He OriginalPaper 09 August 2021 Pages: 953 - 966
The classification of Kleinewillinghöfer types of 2-dimensional Laguerre planes Günter F. Steinke OriginalPaper 02 February 2021 Pages: 967 - 983
Characterization of t-affine differences and related forms Andrzej Olbryś OriginalPaper Open access 05 April 2021 Pages: 985 - 1000