90 Frequency Sounding Techniques for HF Communications over Auroral Zone Paths,Jull, G.W., Doyle, D.J, Irvine, G.W. Murray, J.P., Defence Research Telecommunications Establishment, Ottawa, Ontario, Canada; Proceedings of the IRE, July 1962, Vol 50, No 7, 1676-1682
111 “Canadian Developments (Contributions) to Telecommunications: An Overview of Significant Contributions”. T.L.McPhail and D. C. Coll, Eds. The University of Calgary, 1986.