Kaye, E.J. and Gibbs G.R. (1954) ‘LEO – A Checking Device for Punched Paper Tape’

Electronic Engineering, Vol. 29, pp. 386-392.
Reprinted as part of ‘LEO –Lyons Electronic Office’ in Electronic Engineering, pp 18-24 http://www.bbc.co.uk/blogs/outriders/2011/11/leo_making_history.shtml

Bristol Industrial Archaeological Society Journal (BAIS), No. 47, pages 21-33.