Cognitive Change and Relaxation as Key Mechanisms of Treatment Outcome in Chronic Pain: Evidence From Routine Care oleh Matthias Feldmann, Matthias Feldmann, Hauke Jeldrik Hein, Ulrich Voderholzer, Ulrich Voderholzer, Robert Doerr, Thomas Hoff, Gernot Langs, Philipp Herzog, Philipp Herzog, Tim Kaiser, Winfried Rief, Jenny Riecke, Eva-Lotta Brakemeier, Eva-Lotta Brakemeier