Naeem, S., Ashraf, H., Hayat, A., & Khan, M. A. (2018). COMPARISON OF HEART RATE VARIABILITY IN NEGATIVE AND POSITIVE RESPONDERS TO ACTIVE PHASE OF HEAD-UP TILT TEST.
Pakistan Armed Forces Medical Journal,
68(6), 1566-70.
https://www.pafmj.org/PAFMJ/article/view/2541