 Through translations made available by Danilo Montaldi and others, the Italian autonomists drew upon previous activist research in the United States by the Johnson–Forest tendency and in France by the group Socialisme ou Barbarie.Later, post-Marxist and anarchist tendencies became significant after influence from the Situationists, the failure of Italian far-left movements in the 1970s and the emergence of a number of important theorists including Antonio Negri, who had contributed to the 1969 founding of "Potere Operaio" as well as Mario Tronti, Paolo Virno and Franco "Bifo" Berardi.Unlike other forms of Marxism, autonomist Marxism emphasises the ability of the working class to force changes to the organization of the capitalist system independent of the state, trade unions or political parties.