1. Sztajzel, F., Heart rate variability: A noninvasive electrocardiographic method to measure the autonomic nervous system. Swiss Med. Wkly 134:514–522, 2004.
2. John, D., and MacArthur, C. T., Heart rate variability. Research Network on Socioeconomic Status and Health-Article, 1997.
3. Perciaccante, A., Fiorentini, A., Paris, A., Serra, P., and Tubani, L., Circadian rhythm of the autonomic nervous system in insulin resistant subjects with normoglycemia, impaired fasting glycemia, impaired glucose tolerance, type 2 diabetes mellitus. BMC Cardiovasc. Disord. 6:19, pp. 1–10, May 2006.
4. Al-Hazimi, A., Al-Ama, N., Syiamic, A., Qosti, R., and Abdel-Galil, K., Time—Domain analysis of heart rate variability in diabetic patients with and without autonomic neuropathy. Ann. Saudi Med. 22(5–6):400–403, 2002.
5. Geevarghese, P. J., Abraham, A. K., Annie, P. A., In: Geevarghese, P. J. (Ed.), A Hand Book for Diabetics. 8th Edition. Cochin, India, pp. 8–9, 1999.