Tran, M. V., Ngo, V. T., Nguyen, T. T., Nguyen, T. P., Hoang, T. V. A., Truong, Q. T. and Truong, Q. T. (2025) “Assessment of sleep quality using the pittsburgh sleep quality index (psqi) in patients before cardiac surgery at Hanoi Heart Hospital”, The Vietnam Journal of Cardiovascular and Thoracic Surgery, 52, pp. 139 - 147. doi: 10.47972/vjcts.v52i.1503.