Thomson, John Walter,  1913- <br/><br/>
The lichen genus Cladonia in North America / 
by John W. Thomson. 
 - Toronto :  University of Toronto Press,  1967. 
 - 172 p. :  ill. ;  26 cm. 
<br/><br/>Bibliography: p. 153-158. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cladonia.<br/>Lichens--North America.