Oleg Derzhko, Johannes Richter, Andreas Honecker, and Heinz-Jürgen Schmidt, Universal properties of highly frustrated quantum magnets in strong magnetic fields, Low Temp. Phys. 33, (2007) [Fiz. Nizk. Temp. 33, 982-996, (2007)] DOI: https://doi.org/10.1063/1.2780166.