Downing, John A. <br/><br/>
A Manual on Methods for the Assessment of Secondary Productivity in Fresh Waters 
/ by John A. Downing 
 - London:  Blackwell Scientific Publications,  1984. 
 - xxiv, 501p.; 
<br/><br/><label>ISBN: </label>0632006161 
<br/><br/><label>Dewey Class. No.: </label>574.526  / DOW/A