Unamba, N. N., Edeogu, J. U., & Orji, M. I. (2020). The Functional Class and Electrocardiographic Abnormalities in Heart Failure Patients in Southern Nigeria: A Retrospective Observational Study. The Nigerian Health Journal, 20(2), 44–53. https://doi.org/10.60787/tnhj.v20i2.475