Before revision: Response It was noted by Air Commodore H. E. Whittingham, to be one of the earliest works of its kind, along with that of Air Commodore D. Munro, who wrote on the subject in 1925.
After revision: Response It was noted by Air Commodore H. E. Whittingham, to be one of the earliest works of its kind, along with that of Air Commodore David Munro, who wrote on the subject in 1925.