Complex sentence: The link between these growth rates and the Kosygin reform is, according to Brown, "tenuous", but also admits that "From the point of view of communist rulers, the Brezhnev era was in many ways successful".
Split into simpler sentences: The link between these growth rates and the Kosygin reform is, according to Brown, "tenuous". He also admits that "From the point of view of communist rulers, the Brezhnev era was in many ways successful".