YUGOSLAVIA FREES AMERICAN CITIZEN
Yugoslav-born Amer Laszlo Toth, accused of econ espionage in Yugoslavia, is freed on July 23 after being imprisoned for nearly 1 yr in Yugoslavia; is flown to US; is believed to owe release chiefly to persistent and sometimes bluntly phrased demands of US Amb to Yugoslavia Laurence H Silberman; Silberman charges that he had to contend for last yr with opposition from Yugoslav officials and US State Dept's Eastern Eur sec; adds State Dept not only failed to back his efforts on behalf of falsely accused Amer but has also sought to have him reprimanded for 'undiplomatic conduct'; says Pres Ford and Sec Kissinger agreed with him that US Govt owes complete support to its citizens in such situations; case revd; illus (M)