Noushad, S., S. . Ahmed, B. Ansari, U.-H. . Mustafa, Y. . Saleem, and H. . Hazrat. “Physiological Biomarkers of Chronic Stress: A Systematic Review”. International Journal of Health Sciences, vol. 15, no. 5, Aug. 2021, pp. 46-59, https://ijhs.qu.edu.sa/index.php/journal/article/view/5928.