Referee's report by Dennis Gabor, on a paper 'Perturbation characteristics and their application to electron optics' by P A Sturrock Sectional committee: Mathematics Paper reference code: A90 Recommended for publication in the Philosophical Transactions. Gabor remarks this is a competent paper but far too long and suggests making considerable cuts, detailed in five additional pages. [Published in Proceedings A, 1951]. Date received not given. 1 June 1951