^“Balto-Slavic languages. Encyclopædia Britannica. Encyclopædia Britannica Online”. Encyclopædia Britannica Inc.. 2015年6月閲覧。 “Those scholars who accept the Balto-Slavic hypothesis attribute the large number of close similarities in the vocabulary, grammar, and sound systems of the Baltic and Slavic languages to development from a common ancestral language after the breakup of Proto-Indo-European. Those scholars who reject the hypothesis believe that the similarities are the result of parallel development and of mutual influence during a long period of contact.”
^Kortlandt, Frederik (2009), Baltica & Balto-Slavica, p. 5, "Though Prussian is undoubtedly closer to the East Baltic languages than to Slavic, the characteristic features of the Baltic languages seem to be either retentions or results of parallel development and cultural interaction. Thus I assume that Balto-Slavic split into three identifiable branches, each of which followed its own course of development."
^Derksen, Rick (2008), Etymological Dictionary of the Slavic Inherited Lexicon, p. 20, ""I am not convinced that it is justified to reconstruct a Proto-Baltic stage. The term Proto-Baltic is used for convenience’s sake."