Referee's report by Douglas Rayner Hartree, on a paper 'An integral-equation method of solving plane diffraction problems' by E T Copson Sectional committee: Mathematics Recommended for publication in Proceedings. A final section that summarises the work should be added. He is aware that similar work has been done in government research departments during the war and are not published. He is unsure if this work has been duplicated in this paper. [Published in Proceedings of the Royal Society A, 1946]. Date received not given. 1945