Hopkins, Edward Scott. <br/><br/>
Water purification control / 
Edward Scott Hopkins, Elwood L. Bean. 
 - 4th ed. 
 - Baltimore :  Williams & Wilkins Co.,  1966. 
 - xii, 332 p. :  ill. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Water--Purification