@article{RufFehnBachmannetal.2012,
  author    = {Katharina C. Ruf and Sonja Fehn and Mich{\`e}le Bachmann and Alexander Moeller and Kristina Roht and Susi Kriemler and Helge Hebestreit},
  title     = {Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry},
  year      = {2012},
}