Letter from Sydney Goldstein, on a paper 'Transient source, doublet and vortex solutions of the linearized equations of supersonic flow' by William John Strang to D C Martin, Assistant Secretary of the Royal Society The results have not been anticipated He is unsure if the results were previously published in the Proceedings of the Congress of Applied Mathematics. [Published in Proceedings of the Royal Society A, 1950]. Endorsed on recto as received 18 January 1950. 17 January 1950