Aneta item in De Vrije Pers (31 Jul 1951): on SOBSI's initiative a "17 August" committee was formed in Yogyakarta with trade unions, Front Pemuda, PKI, PSII, Murba, BTI and Gerwis, as an alternative to the city administration's committee, which SOBSI said would only "celebrate a feast".
De Vrije Pers fragment (17 Sep 1953) on trade-union reactions to the Sarbupri plantation workers' strike. It notes that the BTI's second congress, attended by SOBSI, Pemuda Rakyat and Gerwis representatives, declared solidarity with the strike and instructed its branches to support strikers.
Aneta item in De Vrije Pers (13 Feb 1954): nine parties and ten organisations, including PKI, PNI, NU, SOBSI, BTI, Wanita Demokrat, Perwari and Gerwis, met under PNI's R. Kartasasmita and urged the government to dissolve the Greater Jakarta municipal council and form a representative one.