1. 1. "Hypertension" (in en) (html). "Normal blood pressure is when your blood pressure is lower than 120/80 mmHg most of the time". PubMed. Health. 2011.10.06Retrieved 2011.10.16.
2. "Essential Hypertension, Part I: definition and etiology";OA;Circulation,2000
3. 3. Secondary Hypertension, Mayo foundation for medical education and research (2008) [1], Retrieved May 10, 2010.
4. 4. K. Sudhakar, M. Sujatha, S. Rameshbabu, P. Padmavathi and P.P Reddy. Serum calcium levels in patients with essential hypertension and their first degree relatives. Ind J of clinical Biochemistry, 2004, 19(1) 21-23.
5. 5. DM Vasudevan, Sreekumari S. Textbook of Biochemistry for Medical students, 4th Ed. 2005; C (21): 222-223, D(28): 300-303.