Analysis of information sources in references of the Wikipedia article "슬라브조어" in Korean language version.
Its immediate successors were Proto-East Slavic, Proto-South Slavic, and Proto-West Slavic. The Proto-Slavic era itself is often divided arbitrarily into three periods: (1) early Proto-Slavic, until about 1000 B.C.; (2) middle Proto-Slavic, during the next millennium; (3) late Proto-Slavic, from the 1st to the 6th century A.D., although it was not until the 12th century that Slavic linguistic unity actually ceased to function.
