1. Mallmann , W. L. Gelpi , A. G. , Jr. Chlorine resistance of colon bacilli and streptococci in a swimming pool Michigan Eng. Expt. Sta. Bull. 27 3 16 1930
2. Bacteria growing on leather packing cause errors in sampling;Gerstein;Eng. News-Record,1928
3. Bacteria on leather washers; lactose-fermenting organisms growing on leather washers at Chicago;Greer;Water Works and Sewerage,1929
4. Preammoniation at Springfield, Illinois;Spaulding;Jour. Amer. Water Works Assn.,1929
5. Contamination of mains by jute packing;Spaulding;Amer. Jour. Pub. Health,1931