Velz, Clarence J <br/><br/>
Applied stream sanitation / 
Clarence J. Velz 
 - 2nd ed 
 - New York :  Wiley,  1984 
 - viii, 800 p. :  ill. ;  24 cm 
<br/><br/> 'A Wiley-Interscience publication.' 
<br/><br/>Includes bibliographies and indexes 
<br/><br/><label>LCCN: </label>83-23555 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Stream self--purification