Pasaribu, D. A. “HUBUNGAN PEMBERIAN LATIHAN PURSED LIPS BREATHING (PLB) TERHADAP KUALITAS HIDUP KLIEN PENYAKIT PARU OBSTRUKTIF KRONIK (PPOK)”. JURNAL MUTIARA NERS, vol. 2, no. 2, July 2019, pp. 195-02, http://e-journal.sari-mutiara.ac.id/index.php/NERS/article/view/858.