Analysis of information sources in references of the Wikipedia article "Yugoslav colonization of Kosovo" in English language version.
Albanians engaged in armed resistance to Yugoslavia in the form of the Kaçak movement, whose forces numbered around 10,000 armed rebels by 1919... Serbian troops in Kosovo killed 6,040 people and destroyed 3,873 houses in January-February 1919.. One Albanian source claimed that by 1921 the figure reached 12,371 killed..