Prasad, Braj Nandan <br/><br/>
Algal indicators of water pollution 
Braj Nandan Prasad, Yashpal Singh. 
 - Dehradun  Bishen Singh Mahendra Pal Singh  1996 
 - iv,263p., ill.; 22cm. 
<br/><br/><label>Dewey Class. No.: </label>363.7394  / P**A