Folder G.143. Pfeifer, H., 1967-1968. Includes invitation (declined) for Richards to attend conference on radio-frequency spectroscopy in Leipzig. Folders G.144-G.145. Pidcock, A., 1960-1967. Pidcock came from Manchester to do D.Phil. research in Richards's laboratory. 2 folders on research and career. Folder G.145 includes a redraft by Richards of a ms. by Pidcock. Folder G.146. Poindexter, E., 1968, 1972. Correspondence regarding visits to Oxford. Folder…