Citation: Nazarenko, Olga; Kotyrba, Martin R.; Yakunin, Sergii; W\"orle, Michael; Benin, Bogdan M.; Rain\`o, Gabriele; Krumeich, Frank; Kepenekian, Mika\"el; Even, Jacky; Katan, Claudine; Kovalenko, Maksym V. (2019). Guanidinium and Mixed Cesium-Guanidinium Tin(II) Bromides: Effects of Quantum Confinement and Out-of-Plane Octahedral Tilting.. Chemistry of materials : a publication of the American Chemical Society, 31, pp. 2121-2129.