प्रौढ़ ज्ञान विज्ञान | Praudh gyan vigyan 

 - Lucknow  Saksharta niketan prakashan  1988 
 - 67p.  illus. 
 -  part-1 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural sciences
<br/><br/><label>Dewey Class. No.: </label>500  / S29P