1.
Stancheva A, Petrov G, Tzvetkov P, Alexandrov A, Benkova B. State of the research on solar activity impact on the radio waves propagation. YT [Internet]. 2015 Sep. 17 [cited 2024 Nov. 21];2:29-38. Available from: https://ojs.nbu.bg/index.php/YT/article/view/182