Georgakas, D. (1980). The Methuselah factors: Strategies for a long and vigorous life. Simon and Schuster.
Dyfyniad Arddull ChicagoGeorgakas, Dan. The Methuselah Factors: Strategies for a Long and Vigorous Life. New York: Simon and Schuster, 1980.
Dyfyniad MLAGeorgakas, Dan. The Methuselah Factors: Strategies for a Long and Vigorous Life. Simon and Schuster, 1980.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.