▁ 1 9 0 4 . ▁During ▁the ▁winter ▁of ▁ 1 9 0 3 – 0 4 , ▁S ok ol ović ▁attended ▁the ▁newly ▁founded ▁Work ers ' ▁School ▁( Rad ni čka ▁š k ola ) ▁in ▁Bel grade , ▁which ▁was ▁started ▁by ▁Rad ovan ▁Drag ović . ▁Drag ović ▁was ▁one ▁of ▁the ▁found ers ▁the ▁SS DP ▁and ▁the ▁first ▁trade ▁union ▁in ▁Ser bia , ▁the ▁General ▁Work ers ' ▁Union ▁( G lav ni ▁rad ni č ki ▁save z ). ▁Drag ović ▁taught ▁about ▁the ▁labour ▁movement , ▁and ▁the ▁goal ▁of ▁his ▁school ▁was ▁to ▁create ▁efficient ▁social ist ▁ag it ators . ▁ ▁Activ ism ▁in ▁Bos nia ▁and ▁Herz egov ina ▁In ▁Bos nia ▁and ▁Herz egov ina , ▁social ist ▁ideas ▁were ▁first ▁promoted ▁in ▁the ▁ 1 8 6 0 s ▁by ▁Bos n ian ▁Ser b ▁teacher , ▁writer ▁and ▁activ ist ▁V asa ▁Pel ag ić . ▁At ▁that ▁time , ▁near ▁the ▁end ▁of ▁centuries - long ▁Ott oman ▁rule , ▁Bos nia ▁and ▁Herz egov ina ▁was ▁a ▁mostly ▁agr arian ▁and ▁under develop ed ▁province . ▁Its ▁industrial isation ▁began ▁after ▁it ▁was ▁occupied ▁by ▁Austria - H ung ary ▁in ▁ 1 8 7 8 . ▁Many ▁workers ▁were ▁imported ▁to ▁it ▁from ▁more ▁developed ▁parts ▁of ▁the ▁emp ire . ▁Some ▁of ▁them ▁engaged ▁in ▁spread ing ▁social ist ▁ideas ▁in ▁the ▁province , ▁but ▁most ▁of ▁these ▁workers ▁were ▁prompt ly