G. BORTNYK, BORTNYK О., and S. KYRYLYUK, “SPECTRAL-COVARIATION METHOD OF CLASSIFICATION OF RADIO SIGNALS”, Herald of Khmelnytskyi National University. Technical sciences, vol. 317, no. 1, pp. 21–25, Feb. 2023, doi: 10.31891/2307-5732-2023-317-1-21-25.