Comprises:
- D1, D.T. Caminer, and how to avoid them, [?1959].
- D2, Large file, mostly of offprints of articles about LEO but also documents about the LEO library service, description of LEO II, list of jobs using LEO computers, introduction to LEO III, brochure describing LECTOR, advertisements and press releases, from Frank Land, 1953-1980s.
- D3 Political & Economic Planning, The LEO Computer: a case study in the use of an electronic computer in routine clerical work, reprinted from Three Case Studies in Automation, July 1957.
- D4, Various news cuttings re LEO computers, 1970s and 1980s.
- D5, Folder, LEO press cuttings, 1980s.
- D6, Folder, photocopies of LEO press cuttings, 1950s.
- D7, Folder, photocopies of LEO press cuttings, 1950s.
- D8, Brochure: "LEO: the automatic office that revolutionised the whole conception of office practice" n.d.
- D9, Offprint "Bakery Sales Control by LEO" reprinted from Office Magazine January 1957
- D10, "Leo:a computer in the service of the steel industry" (Stewarts and Lloyds, 1958).
- D11, Handbook for the staff of LEO Computers ltd., 1962.
- D12, "Leo Computers" reprinted from Engineering 5 March 1965
- D13, G A Randall, 'The potentialities of a Computer in the Smaller Office" the Accountant 19 September 1959.
- D13, "The scope for Electronic Computers in the office" reprint of a paper submitted to the Office Management Association conference, 1955.
- D14, H Paul Ruglys, '"the most significant advancement in computing in the last thirty years: Lyons Electronic Office", typescript article, n.d. [prob 1970s].
- D15, "Diminishing returns" repr. from Engineering 23 December 1955.
- D16, "Conversation with J M M Pinkerton" Annal for the history of computing Jan 1983.