Lichens :
an illustrated guide to the British and Irish species /
Frank S. Dobson.

APA Citation

Dobson, F. (Frank S.). (2005). Lichens: an illustrated guide to the British and Irish species. 5th ed. Slough: Richmond.

MLA Citation

Dobson, Frank (Frank S.). Lichens: an Illustrated Guide to the British And Irish Species. 5th ed. Slough: Richmond, 2005.

Warning: These citations may not always be complete (especially for serials).