Please answer a question about the following article about Greece:

Near the northern Greek borders there are also some Slavic–speaking groups, locally known as Slavomacedonian-speaking, most of whose members identify ethnically as Greeks. Their dialects can be linguistically classified as forms of either Macedonian Slavic or Bulgarian. It is estimated that after the population exchanges of 1923, Macedonia had 200,000 to 400,000 Slavic speakers. The Jewish community in Greece traditionally spoke Ladino (Judeo-Spanish), today maintained only by a few thousand speakers. Other notable minority languages include Armenian, Georgian, and the Greco-Turkic dialect spoken by the Urums, a community of Caucasus Greeks from the Tsalka region of central Georgia and ethnic Greeks from southeastern Ukraine who arrived in mainly Northern Greece as economic migrants in the 1990s.

Where are Slavic speaking groups generally found?
northern Greek borders