1. Straker, T. W.; The ionospheric propagation of radio waves of frequency 16 kc/s over short distances (Not yet published).
2. Bracewell, R. N.; The ionospheric propagation of radio waves of frequency 16 kc/s over distances of about 200km (Not yet published).
3. Bain, W. C., Bracewell, R. N., Straker, T. W. and Westcott, C. H.; The ionospheric propagation of radio waves of frequency 16 kc/s over distances of about 550 km (Not yet published).