Gray, J. A. (1971). The psychology of fear and stress. McGraw-Hill.
Dyfyniad Arddull ChicagoGray, Jeffrey Alan. The Psychology of Fear and Stress. New York: McGraw-Hill, 1971.
Dyfyniad MLAGray, Jeffrey Alan. The Psychology of Fear and Stress. McGraw-Hill, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.