Letter from John Combridge of Ilford, Essex, about his work on Korean clockwork and accompanying copies of correspondence with Gari Ledyard of Columbia University, New York, U.S.A., about his assistance with the work, 1964-12-22 - 1965-01-04, GBR/1928/NRI/NRI2/2/4/4/33. The Papers and Possessions of Joseph Needham, GBR/1928/NRI/NRI2. Needham Research Institute. https://archivesearch.lib.cam.ac.uk/repositories/21/archival_objects/331141 Accessed July 05, 2024.