BIBLIOGRAPHY

[1] Letton. J. Amer. Waterworks Assoc., 1915, 2, 688.

[2] Kienle. J. Amer. Waterworks Assoc., 1915, 2, 690.

[3] Adams. J. Amer. Pub. Health Assoc., 1916, 6, 867.

CHAPTER VI