1. G. Kurze and W. Wallenfels, “Methods of Enzymatic Analysis,” 2nd Ed., Vol. III, ed. by H. U. Bergmeyer, Verlag Chemie GmbH, Weinheim, 1974, p. 1279.
2. “Bergey’s Manual of Determinative Bacteriology,” 8th Ed., ed. by S. T. Cowan, J. G. Holt, J. Liston, R. G. E. Murray, Ç. F. Niven, A. W. Ravin and R. Y. Steiner, Williams & Wilkins Co., Baltimore, 1974, p. 669.