1. Introductory Fourier Transform Spectroscopy;Bell,1972
2. Ion–ion interactions and exciton effects in rare earth insulators;Cone,1987
3. Optical magnetic excitations;Eremenko;Phys. Rep,1986
4. Optical spectroscopy of lanthanides in crystal matrix;Hüfner,1982
5. Rare earth spectroscopic probe in physics of magnetics;Popova,1996