1. G. L. Cote and J. A. Ahlgran, in “Science and Technology of Fructans. Metabolism in Microorganisms, Part I: Levan and Levansucrase,” ed. by M. Suzuki and N. J. Chatterton, CRC Press, Boca Raton, FL, 1993, pp. 141–168.
2. J. De Lay, J. Swings, and F. Gossele, in “Bergey’s Manual of Systematic Bacteriology,” ed. by N. R. Krieg and J. G. Holt, Williams & Wilkins Co., Baltimore, 1984, pp. 268–278.