Inaugurated by Silviu Brucan's public criticism of the Braşov repression, and inspired by the impact of changes in other Eastern Bloc countries, protests of marginalized PCR activists became notorious after March 1989, when Brucan and Pârvulescu, together with Gheorghe Apostol, Alexandru Bârlădeanu, Grigore Răceanu and Corneliu Mănescu, sent Ceaușescu their so-called "Letter of the Six", publicized over Radio Free Europe. At around the same time, systematization provoked an international response, as Romania was subjected to a resolution of the United Nations Commission on Human Rights, which called for an inquiry into the state of ethnic minorities and the rural population; the political isolation experienced by Communist Romania was highlighted by the fact that Hungary endorsed the report, while all other Eastern bloc countries abstained. This followed more than a decade of deteriorating relations between the PCR and the Hungarian Socialist Workers' Party.