Water plants of the world :  a manual for the identification of the genera of freshwater macrophytes / 
by Christopher D.K. Cook ... [et al.] 
 - The Hague :  W. Junk,  1974 
 - viii, 561 p. :  ill. ;  23cm. 
<br/><br/><label>ISBN: </label>9061930243 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freshwater flora--Identification