@misc{Frahm2013,
  author    = {Jan-Peter Frahm},
  title     = {The differentiation of sterile thalli of Aneura and Pellia and the problem of Pellia species with unistratose margins},
  booktitle = {189},
  series    = {Archive for Bryology},
  number    = {189},
  type      = {periodicalpart},
  pages     = {6},
  year        = {2013},
}