वर्मा, फूलदेव सहाय <br/><br/>
कोयला  
Koyala 
 - 1st ed. 
 - Uttar Pradesh  Prakashan Shakha  1958 
 - 11485 p. 
 - Hindi Samiti Granthamala  18 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sciences
<br/><br/><label>Dewey Class. No.: </label>छ.३  / वर्मा