Gunashekar, S. D., Warrington, E. M., Strangeways, H. J., Erhel, Y., Salous, S., Feeney, S. M., Abbasi, N. M., Bertel, L., Lemur, D., Marie, F., & Oger, M. (2009). Utilization of antenna arrays in HF systems. Annals of Geophysics, 52(3-4), 323–338. https://doi.org/10.4401/ag-4578