@article{MummHermanussenScheffler2016,
  author    = {Rebekka Mumm and Michael Hermanussen and Christiane Scheffler},
  title     = {voice break as the marker of biological age},
  journal   = {Acta paediatrica : nurturing the child},
  volume    = {105},
  pages     = {e459 -- e463},
  doi       = {10.1111/apa.13488},
  year      = {2016},
}