The Socialist German Student Association (SDS)
The West German SDS was founded in 1946 as a social-democratic student organisation. However, due to its left-wing positions, the SPD issued an incompatibility declaration against it in 1961.
Whereas during the early 1960s left-wing socialist and socialist-councilist influences had played a major role in the association, after 1968, when it reached its climax, the SDS became increasingly polarised between an anti-authoritarian and a traditionalist wing. The organisation was finally dissolved in 1970. Texts by and about the SDS can, for example, be found here and here.