1. W. Wallace and A. Oaks, “Plant Proteolytic Enzymes,” Vol. II, ed. by M. J. Dalling, CRC Press, Boca Raton, Florida, 1986, pp. 81 ~ 89.
2. D. Gershon, A. Reznick and U. Reiss, “Physiology and Cell Biology of Aging,” ed. by A. Cherkin, Raven, New York, 1979, pp. 21 ~ 26.