Links we like:

FamilyHealth.NETwork 

Health and High Blood Pressure
CASA - FLIGHT SAFETY AUSTRALIA, SEPTEMBER-OCTOBER 2001

Clinical effects of Hibiscus sabdariffa on hypertension
Australian Journal of Medical Herbalism, Spring, 2007 by Cara Barnes

PubMed Central (PMC) is the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature: Search for "Hibiscus Subdariffa"

FAA - Hypertension information from Pilot Medical Solutions

FAA Medications Master List from Pilot Medical Solutions

High blood pressure: How it can harm your health (MBF Australia)

New World Gourmet - Germany