Complex sentence: The letter was first used in print in 1795 by the poet Ivan Dmitriev and was soon taken up by such influential writers as Nikolai Mikhailovich Karamzin and Gavrila Romanovich Derzhavin, which assured its acceptance in the literary norm.
Split into simpler sentences: The letter was first used in print in 1795 by the poet Ivan Dmitriev. It was used by such influential writers as Nikolai Mikhailovich Karamzin and Gavrila Derzhavin, which assured its acceptance in the literary norm.