Sublobar resection, radiofrequency ablation or radiotherapy in stage I non-small cell lung cancer - Safi, Seyer; Rauch, Geraldine; Winkel, Jan op den; Kunz, Josef; Heußel, Claus Peter; Huber, Peter E.; Herth, Felix; Dienemann, Hendrik; Hoffmann, Hans (Respiration, 2015)