Despatch by H. E. Field-Marshal Sir William Riddell Birdwood, C-in-C in India, on the disturbances on the North-West Frontier of India from 23rd April to 12th September 1930. London: Air Ministry, 1932.
An examination by the General Staff India of the Air Staff memorandum entitled 'What air control means in war and peace and what it has achieved'. Simla: GSI, 1931.