1. Cracks in Filter Beds;Baylis;W. W. and Sew.,1930
2. Filter Bed Clogging;Baylis;W. W. and Sew.,1930
3. “Cleaning Filter Sand.” (Round Table Discussion.);Journal, North Carolina Section, A. W. W. A.,1931
4. Breaking up Mud-Balls in a Filter;Gosnell;W. W. and Sew.,1929
5. Reduction of Mud-Balls in Rapid Sand Filters;Graf;Eng. News-Rec.,1926