AlberY.I.and Guerre-DelabriereS.,“PrincipleofweaklycontractivemapsinHilbertspaces”,NewresultsinOperatorTheoryanditsApplications,(1997),7-22.
Aydi H., Chen C.M., Karapinar E., “Interpolative Ćirić-Reich-Rus type contractions via the Branciari distance”, Mathematics, 7(1)(2019), 84.