A collection of Ramsey's manuscripts, including notes, lectures, unfinished writings, amounting to 120 items and approximately 1,200 holograph items, is held as part of the Archives of Scientific Philosophy in the Twentieth Century in the Hillman Library of the University of Pittsburgh, U.S.A.; see F. P. Ramsey, 'On truth: original manuscript materials (1927-1929) from the Ramsey Collection at the University of Pittsburgh', edited by Nicholas Rescher and Ulrich Majer, Dordrecht: Kluwer, 1991. These papers are available on microfilm, ref MS MF 6634/5 and MS MF 8602. A postcard from Ramsey to C. K. Ogden, about Wittgenstein, 1923, is at CUL MS Add. 8812/124. Letters from Ramsey to G. E. Moore, 1924-9, are at CUL MS Add. 8330/8R/3/1-5