March 1 (SeeNews) - Croatian car parts maker AD Plastik [ZSE:ADPL], food and pharmaceuticals producer Podravka [ZSE:PODR] and port operator Luka Ploce [ZSE:LKPL] find it hard to predict the impact of the Russian invasion of Ukraine on their business, according to a poll of four local listed companies carried out by the Zagreb bourse.