| RefNo | Title | Date |
| EC/1942/17 | Thoday, David: certificate of election to the Royal Society | |
| NLB/40/700 | Copy letter from John Rose Bradford to D [David] Thoday | 19 July 1909 |
| RR/17/446 | Referee's report by Francis Darwin, on a paper 'Experimental researches on vegetable assimilation and respiration V.—A critical examination of Sachs’ method for using increase of dry weight as a measure of carbon dioxide assimilation in leaves' by David Thoday | 19 June 1909 |
| NLB/42/95 | Copy letter from Robert William Frederick Harrison to D [David] Thoday, Botany School, Cambridge | 23 March 1910 |
| NLB/38/143 | Copy letter from Robert William Frederick Harrison, to [David] Thoday, [Fellow of the Royal Society], Trinity College, Cambridge | 19 June 1908 |
| NLB/39/268 | Copy letter from Robert William Frederick Harrison to D Thoday, 26 Portugal PLace, Cambridge | 17 December 1908 |
| NLB/40/195 | Copy letter from Robert William Frederick Harrison to D [David] Thoday, Trinity College, Cambridge | 30 April 1909 |
| NLB/40/136 | Copy letter from Robert William Frederick Harrison to D Thoday | 23 April 1909 |
| NLB/41/105 | Copy letter from Robert William Frederick Harrison, to [David] Thoday, [Fellow of the Royal Society] | 13 October 1909 |
| NLB/40/642 | Copy letter from Robert William Frederick Harrison to D [David] Thoday, 26 Portugal Place, Cambridge | 12 July 1909 |
| NLB/40/482 | Copy letter from Robert William Frederick Harrison to Dr F [Frederick] F [Frost] Blackman FRS | 14 June 1909 |
| NLB/40/521 | Copy letter from Robert William Frederick Harrison to D [David] Thoday | 18 June 1909 |
| NLB/42/135 | Copy letter from Robert William Frederick Harrison to Professor F [Francis] W [Wall] Oliver FRS | 11 April 1910 |
| NLB/42/373 | Copy letter from Robert William Frederick Harriton to D Thoday, MA | 30 May 1910 |
| NLB/41/437 | Copy letter from Robert William Frederick Harrison, to [David] Thoday, [Fellow of the Royal Society], Botany Schools, Cambridge | 14 December 1909 |
| NLB/42/67 | Copy letter from Robert William Frederick Harrison to Dr J [John] R [Rose] Bradford, Sec RS | Undated |
| RR/70/100 | Referee's report by David Thoday, on a paper 'Quantitative studies on the wetting of leaves by water' by Gordon Elliott Fogg | 1947 |
| RR/18/87 | Referee's report by Horace Tabberer Brown, on a paper 'Experimental researches on vegetable assimilation and respiration. VI.—Some experiments on assimilation in the open air' by David Thoday | 13 March 1910 |
| IM/GA/GRS/6367 | Thoday, David | nd |
| NLB/39/603 | Copy letter from Robert William Frederick Harrison to D [David] Thoday, 26 Portugal Place, Cambridge | 12 February 1909 |