Personal diaries, 1939-1942, 1958-1959, 1967-1968, including observations on Kenya, Tanganyika and Somaliland Official desk diaries, 1956, 1958-1964 Observations by Trevaskis on the ecology of Northern Rhodesia, [1939]; The Northern Rhodesia Journal, June 1950, containing articles on the region's history, natural history and sociology …

Typescript social survey of the Hamasien, Eritrea, 1944 Notes, survey, report, etc. on Eritrea's history, inhabitants, etc., [1940s?] Photographs of Trevaskis and family, [1940s?] Papers concerning the Four Power Commission of Investigation of the Former Italian Colonies (Eritrea), 1947 Papers concerning the appointment of the United Nations…