1. http://www.urmc.rochester.edu/smd/ca/dh/index.html
2. John A http://www.jhartfound.org/fi.htm
3. Solomon DH Burton JR http://www.americangeriatrics.org/docs/jahnigen_update_fall_02.doc
4. Donald W. http://www.dwreynolds.org/Programs/National/Aging/AboutAging.htm