[45] Lipman, C. B., and Burgess, P. S., Centr. f. Bakt., 1915, Abt. II., Bd. 44, p. 481.
[46] Lipman, C. B., and Waynick, D. O., Soil Sci., 1916, vol. i., p. 5.
[47] Löhnis, F., and Pillai, N. K., Centr. f. Bakt., 1908, Abt. II., Bd. 20, p. 781.
[47b] Löhnis, F., and Smith, T., Journ. Agric. Res., 1914, vol. vi., p. 675.
[48] Mackenna, J., Rept. Prog. Agric., India, 1917, p. 101.
[49] Marchal, E., Bull. Acad. Roy. Belgique, 1893, vol. xxv., p. 727.
[50] McBeth, I. G., and Scales, F. M., U.S. Dept. Ag., Bureau Plant Indus., 1913, Bulletin 266.
[51] Mockeridge, J., Biochem. Journ., 1915, vol. ix., p. 272.
[52] Nabokich, A. J., and Lebedeff, A. F., Centr. f. Bakt., 1906, Abt. II., Bd. 17, p. 350.
[53] Nagaoka, M., Bull. Coll. Agr., Tokyo, 1900, vol. vi., No. 3.