Merdeka, 6 April 1951, hlm. 2: konferensi Serikat Buruh Batik
Merdeka, 6 April 1951: Batik Workers' Union conference
Merdeka, 6 Apr 1951, p. 2: Serikat Buruh Batik conference on fusion with the textile union; Gerwis listed among the guests and those who gave greetings, with SOBSI and MPs Werdojo and Pardede.