Alexander, (George Alexander, GHA) Die and Mould Production Handbook. Slim but useful guide to using Diesinking and Engraving Machines with examples of how to mount and employ the various accessories: Spacing Piece, cam Forming Arm, Rotary table, Swivel Vice, Etching Pencil and Transformer, Auxiliary Work tables, Cylinder and Roller Engraving Devices, G.H.A.