Locomotive test report, London Midland & Scottish Railway Report No. 28, standard Class 7 locomotive 0-8-0 No. 9596, No. 9518, No. 9519, No. 9593, performance and efficiency with various types of valves and sizes of cylinder, Schmidt type piston valves August 1930, Derby, 9 pages of text, 4 diagrams, 2 tables. (NRM Technical Archive reference TEST/LMS/23)