According to the book “Međunarodni saučni skup povidon 100-godjosnice ustanaka u Bosni i Herzegovinja, drugim balkanskim zemljem i istočnoj krizi 1875-1878. god Sarajevo-Ilidža, 1-3”, published October 1975, in Volume 2, from 1977, we can find a quote by M.V. Smiljanić in 1905 regarding the Albanians in southern Serbia.

Cited:

“As early as 1905, M.V. Smiljanić stated, among other things: “Today, it is true that the Albanian population in southeastern Serbia is found in several villages (Tupale, all Albanian; Drvodelje, half Serbian, half Albanian; Radevce, mostly Albanian; Sjerinje, both Serbs and Albanians, etc.), but before the Serbian-Turkish war of 1878, it was completely different. Until then, the majority of the population in today’s Toplica and part of the Vranje district was of Albanian ethnicity (…)

Before the Serbian-Turkish war, the Prokupac district had 2,031 Serbian, 74 Turkish, 2,054 Albanian and 200 Circassian houses. After the war, 60 villages remained in this district.”

Reference

https://www.google.se/books/edition/Me%C4%91unarodni_nau%C4%8Dni_skup_povodom_100_go/L0WPAAAAIAAJ?hl=sv&gbpv=1&bsq=Joksim+Kne%C5%BEevi%C4%87&dq=Joksim+Kne%C5%BEevi%C4%87&printsec=frontcover