Akhter, Q. F., Akhter, Q. S., Rahman, F., Ferdousi, S., & Sinha, S. (2014). Power spectral analysis of heart rate variability in Bangladeshi healthy population of different age. Bangladesh Journal of Physiology and Pharmacology, 30(1), 11–15. https://doi.org/10.3329/bjpp.v30i1.20788