Davis, P. H. <br/><br/>
The identification of flowering plant families, including a key to those native and cultivated in North temperate regions / 
P. H. Davis, J. Cullen. 
 - 2nd ed. 
 - New York :  Cambridge University Press,  1979. 
 - 113 p. ;  20 cm. 
<br/><br/>Includes index. 
<br/><br/> Open access. 
<br/><br/><label>ISBN: </label>0521293596 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Angiosperms--Identification.<br/>Flowers--Identification.