1. M. R. J. Salton, “The Bacterial Cell Wall,” Elsevier Publishing Co., Amsterdam, 1964.
2. J.M. Ghuysen, J. L. Strominger and D. J. Tipper, “Comprehensive Biochemistry,” Vol. 26A, ed. by M. Florkin and E. H. Stotz, Elsevier Publishing Co., Amsterdam, 1968, pp. 53~104.