1. Über Madelungfaktoren
2. ICSD-Database FIZ/NIST. Fachinformationszentrum Karlsruhe, Germany, National Institute of Standards and Technology, Geithersburg. USA, Vers. 1.3.3.
3. K. Brandenburg, DIAMOND - Crystal and Molecular Structure Visualization. Crystal Impact GbR, Bonn, Vers. 2.1.