1. W. D. Miller, “Microorganisms of the Human Mouth,” S. S. White Publ. Co., Philadelphia, Pensylvania, 1890.
2. “The Actinomycetes,” Vol. II. ed. by S. A. Waksman, The Williams & Wilkins Co., Baltimore, 1961.
3. “Bergey’s Manual of Determinative Bacteriology,” 7th. Ed., ed. by R. S. Breed, E. G. D. Murray and N. R. Smithet al., The Williams & Wilkins Co., Baltimore, 1958.