BTM Internal Directories  c1940-1959

AEI and Metro-Vickers Internal Directories  c1955

BTM Papers and Magazines  c1940-1958

The BTM Tabulator Magazines  c1940-1958

These were described as a “monthly bulletin” for customers, the first edition was Dec 1936.

They ended when BTM and Powers-Samas merged during 1959 to form ICT.