Theatre London :
an authoritative guide book to London theatres /
compiled by the British Centre of the International Theatre Institute in association with Unesco.

APA Citation

London Transport Executive., Unesco., International Theatre Institute. British Centre. (1980). Theatre London: an authoritative guide book to London theatres. London: London Transport Executive.

MLA Citation

London Transport Executive, Unesco, and International Theatre Institute. British Centre. Theatre London: an Authoritative Guide Book to London Theatres. London: London Transport Executive, 1980.

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