<https://senngroup.com/tolerance-factor-control-of-uniaxial-negative-thermal-expansion-in-a-layered-perovskite/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://senngroup.com/tolerance-factor-control-of-uniaxial-negative-thermal-expansion-in-a-layered-perovskite/>