Polhamus, L.G.  <br/><br/>
Plants collected and tested by Thomas A. Edison as possible sources of domestic rubber  (Book) 

 - Beltsville  United States Department of Agriculture  1967 
 - 191p.  26 cm. 
<br/><br/><label>Universal Decimal Class. No.: </label>633.91:001.4:678.4 POL  / 2433