| RefNo | Title | Date |
| TG/1/2/2 | Letter from Thomas Gold to Professor Harry Hemley Plaskett, Oxford | 2 July 1964 |
| RR/70/185 | Referee's report by Harry Hemley Plaskett, on a paper 'On interference microscopy' by Thomas Ralph Merton | 1947 |
| RR/69/208 | Referee's report by Harry Hemley Plaskett, on a paper 'A contribution to the theory of the Foucault test' by E H Linfoot | 1945 |
| RR/72/195 | Referee's report by Harry Hemley Plaskett, on a paper 'On the reproduction and ruling of diffraction gratings' by Thomas Ralph Merton | 19 December 1949 |
| IM/003597 | Plaskett, Harry Hemley | 1947 |
| EC/1936/13 | Plaskett, Harry Hemley: certificate of election to the Royal Society | |
| RR/71/110 | Letter from Harry Hemley Plaskett, to David Christie Martin, regarding a paper 'Microscopy by reconstructed wave-fronts' by Dennis Gabor | 21 September 1948 |
| AP/81/14 | Unpublished paper, 'Wind waves. Visible, directional and approximately horizontal contact waves at the interface of atmospheric strata' by Catherine [Catharine] O [Octavia] Stevens | 1927-1940 |
| AP/81/14/1 | Unpublished manuscript, 'Wind waves. Visible, directional and approximately horizontal contact waves at the interface of atmospheric strata' by Catherine [Catharine] O [Octavia] Stevens | 1927-1940 |
| AP/81/14/2 | Unpublished appendix, regarding 'Wind waves. Visible, directional and approximately horizontal contact waves at the interface of atmospheric strata' by Catherine [Catharine] O [Octavia] Stevens | 5 December 1939 |
| AP/81/14/3 | Unpublished correspondence, regarding 'Wind waves. Visible, directional and approximately horizontal contact waves at the interface of atmospheric strata' between Catherine [Catharine] O [Octavia] Stevens, H H [Harry Hemley] Plaskett, A C G [Alfred Charles Glyn] Egerton, G M B [Gordon Miller Bourne] Dobson and S [Sydney] Chapman | 5 July 1935-22 April 1940 |
| RR/79/67 | Referee's report by Harry Hemley Plaskett, on a paper 'Argon vacuum wavelength measurements' by T A Littlefield and D T Turnbull | 8 April 1953 |
| RR/77/175 | Referee's report by Harry Hemley Plaskett, on a paper 'An attempt to measure interferometrically the widths of chromospheric lines at the total solar eclipse of 1952 February 25' by H A Bruck and Derek Ainslie Jackson | 2 September 1952 |
| RR/77/176 | Letter from Harry Hemley Plaskett, on a paper 'An attempt to measure interferometrically the widths of chromospheric lines at the total solar eclipse of 1952 February 25' by H A Brück and Derek Ainslie Jackson, to D C Martin, assistant secretary of the Royal Society | 20 September 1952 |