You can do simple searches using this form:

Type	Originator	Title	Date
	Messenger,M.J	Caradon and Looe, The Canal, Railways and Mines	1978
	Farr,M	Diving in darkness	2003
	Bradshaw,J, Caiger,N, Halpin,M, le Gear,R	Kent and East Sussex Underground	1991
	Boyle,M.E	Man Before History	1939
	Lake,K & Poynter,D (eds)	Proc. of the 2011 NAMHO Conf. 50 years of Mine Exploration	2014
	Lock. D	Secrets of the Cave	2015
	Guillot,F & Bence,P	SpeleoGuide Ariege Pyrenees (Tome 1)
	Buckley,A	The Great County Adit	2016
	Symons,S	The Wonders of Dan yr Ogof	2003
	Waltham,A.C	The World of Caves	1976
	Watson,R. A (ed)	The suckers visit to the Mammoth Cave	1970
	Deming,J & Zhaoyang,W	Underground Worlds-Guizhou China	1993
	Warild, Alan	Vertical
	Hofman,P	Wege in Istrien	2007
	Bellamy,D	Wilderness Artist	1995