VNUKOVICH, Y. “ETHNIC IDENTIFICATION OF BELARUSIANS AND LITHUANIANS BASED ON THE "SPEECH SAMPLES" COLLECTED BY P.I. KÖPPEN IN 1827”. Vestnik of Polotsk State University. Part A. Humanities, no. 3, July 2025, pp. 84-99, doi:10.52928/2070-1608-2025-75-3-84-99.