Smartphone-Based Physical Activity Telecoaching in Chronic Obstructive Pulmonary Disease: Mixed-Methods Study on Patient Experiences and Lessons for Implementation oleh Loeckx, Matthias, Rabinovich, Roberto A, Demeyer, Heleen, Louvaris, Zafeiris, Tanner, Rebecca, Rubio, Noah, Frei, Anja, De Jong, Corina, Gimeno-Santos, Elena, Rodrigues, Fernanda M, Buttery, Sara C, Hopkinson, Nicholas S, Büsching, Gilbert, Strassmann, Alexandra, Serra, Ignasi, Vogiatzis, Ioannis, Garcia-Aymerich, Judith, Polkey, Michael I, Troosters, Thierry