@article{AlbersWittrock2013,
  author    = {Klaus Albers and Ulrich Wittrock},
  title     = {Optical pump concepts for highly efficient quasi-three-level lasers},
  journal   = {Appl. Phys. B},
  volume    = {105},
  pages     = {245 -- 254},
  doi       = {10.25974/fhms-646},
  year      = {2013},
}