Ellis, D. R. <br/><br/>
Hard and soft water / 
D. R. Ellis. 
 - Oxford :  Pergamon Press,  1970. 
 - iv. (various pagings). ;  10 cm. 
 - A Pergamon practical programme .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Water.<br/>Water--Hardness.