Velz, Clarence J. <br/><br/>
Applied stream sanitation / 
Clarence J. Velz 
 - 2nd ed. 
 - NewYork :  Wiley,  1984 
 - viii, 800 p. :  ill. ;  24 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Stream self-purification
<br/><br/><label>Dewey Class. No.: </label>628.168 VEL