P. J. Cowan
- Lieut-Colonel Percy John Cowan, 1876-1954. Dans: Proceedings of the Institution of Civil Engineers, v. 4, n. 4 (juillet 1955). (1955):
- American Locomotive Practice. Dans: Minutes of the Proceedings of the Institution of Civil Engineers, v. 154, n. 1903-4 ( 1903). (1903):