1. N. Krieg, P. Sneath, and J. Holt, in “Bergey’s Manual of Systematic Bacteriology,” Vols. 1 and 2, Williams & Wilkins, Baltimore, 1986, pp. 1–1599.
2. T. Mitsuoka, in “Chonai-flora no Kenkyu Hohoron” (in Japanese), Japan Scientific Societies Press, Tokyo, 1989, pp. 1–245.