Cardona, M. Former Departments, Max Planck Institute for Solid State Research, Max Planck Society;
Martin, A. A., Cardona, M., Jandl, S., Nekvasil, V., & Wolf, T. (2000). Optical study of crystal-field excitation in (R)Ba2Cu3O7-δ single crystals. physica status solidi (b), 220, 475-482.