Finnic languages
The Finnic (also known as Baltic-Finnic) languages originate from a common protolanguage, Proto-Finnic, which means they are closely related to each other. As the name Baltic-Finnic implies, these languages are spoken in the region around the Baltic Sea.
Sources:
Planning a new standard language. Finnic minority languages meet the new millennium. Eds. Helena Sulkala & Harri Mantila. Finnish Literature Society 2010.
Facing Finnic. Some Challenges to Historical and Contact Linguistics. Ed. Johanna Laakso. Castrenianumin toimitteita 59, Mémoires de la Société Finno-Ougrienne.
The map can be downloaded here.