@inbook {504,
	title = {Biological recording of changes in British wildlife},
	volume = {ITE Symposium No. 20},
	year = {1992},
	publisher = {HMSO},
	organization = {HMSO},
	chapter = {Evidence for the effects of atmopheric pollution on bryophytes from national and local recording.},
	address = {London},
	author = {Adams, K.J. and Preston, C.D. and Harding, P.}
}
