Welch, Paul Smith,  1882- <br/><br/>
Limnological methods / 
by Paul S. Welch. 
 - New York :  McGraw-Hill,  1948 
 - xviii, 381 p. :  ill. ;  24 cm. 
<br/><br/>Includes bibliograhpies. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freshwater biology--Research