Bir, S.S. <br/><br/>
Pteridophytes (Aspects of plant sciences) 
S.S. Bir. 
 - New Delhi  Today and Tomorrow Printers  and  Publishers  1990 
 - vii, 252p., ill.; 22cm. 
<br/><br/><label>Dewey Class. No.: </label>587  / B55P