 Stieber's work in the 1930s represented some of the first studies of the dialect of the Lemko Rusyns.The deportation of this ethnic group in Operation Vistula after World War II underlines the importance of Stieber's work carried out while the community was still intact.Stieber also produced works on the history and development of Polish (1934), Czech (1957), and Slavic in general (1969).