Defi Eka Kartika; Rosyadi, I.; Sandra; Noviyani, D.; Veralia; Yolanda, M. Smartphone Video Education-Based Diaphragmatic Respiratory Intervention As An Effort To Improve The Comfort Of Breast Cancer Patients Who Undergoing Chemotherapy At Arifin Achmad Hospital Riau Province. IPK 2024, 3, 30-41.