Ambreen, Shazadi, Humaira Fayyaz Khan, Azmat Hayyat, and Nasar Abbas Shamsi. “Association of Age and Symptoms With Frequency of Premature Ventricular Contractions on 24 Hours Holter monitoring”. Pakistan Journal of Medical Sciences 37, no. 2 (February 3, 2021). Accessed March 28, 2024. https://pjms.org.pk/index.php/pjms/article/view/2873.