Seminars. Correspondence with visiting speakers, arrangements and notices for seminars. Internal seminars were also held, the first being on 23 September 1975. Folder H.266. 1975. Folder H.267. 1976. Folder H.268. 1977. Folder H.269. 1978. Folder H.270. 1979. Folder H.271. 1980. Folder H.272. 1981. Folder H.273. "Heads of Groups" meetings, informal discussions and talks to acquaint…