Complex sentence: No other radical economic reforms were carried out during the Brezhnev era, and economic growth slowed down in the early-to-mid-1970s and by Brezhnev's death in 1982 it had, according to some historians, nearly come to a standstill.
Split into simpler sentences: No other radical economic reforms were carried out during the Brezhnev era, and economic growth began to stagnate in the early-to-mid-1970s. By Brezhnev's death in 1982, Soviet economic growth had, according to several historians, nearly come to a standstill.