Youngken, Heber W.  1885-1963. <br/><br/>
Pharmaceutical botany :  a text-book for students of pharmacy and science / 
Heber W. Youngken 
 - 3rd ed. 
 - Philadelphia :  P. Blakiston's son & co.,   [c1921] 
 - xix, 479p. :  incl. front., ill. ;  20cm.