Question: Who proclaimed that the author of the play "The Twelve Months" was the founder of Russia's children's literature?
Sentence (from "Samuil Marshak"): Samuil Yakovlevich Marshak (alternative spelling: Samuil Yakovlevich Marchak) (; 3 November [O.S. 22 October] 1887 4 July 1964) was a Russian Jewish and Soviet writer, translator and children's poet.
Relevant evidence: No