Lichenology :  progress and problems ; proceedings of an international symposium held at the University of Bristol / 
edited by D.H. Brown, D.L. Hawksworth and R.H. Bailey. 
 - London :  Academic Press for the Systematics Association and the British Lichen Society,  1976. 
 - 551p. :  ill. ;  24 cm. 
<br/><br/><label>ISBN: </label>0121367509 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Lichens--Congresses.