1. Howell A. R. Anomalies Associated with the Polytropic Expansion of Air Through a Convergent Nozzle. 1964.
2. Reply to Communications from Stratford, B. S. and Naylor, V. D.;Bragg;Journal of the Royal Aeronautical Society,1964
3. The Speed of Sound and Mach Number Effects
4. Dimensionless Kinetic Energy: A New Parameter for Gas Flow in Ducts with Application to Nuclear-Power Reactors
5. Keenan J. H. and Neumann E. P. Friction in Pipes at Supersonic and Subsonic Velocities. NACA TN 963, 1944.