In the Soviet Union, the use of Hebrew, along with other Jewish cultural and religious activities, was suppressed. Soviet authorities considered the use of Hebrew "reactionary" since it was associated with Zionism, and the teaching of Hebrew at primary and secondary schools was officially banned by the People's Commissariat for Education as early as 1919, as part of an overall agenda aiming to secularize education (the language itself did not cease to be studied at universities for historical and linguistic purposes). The official ordinance stated that Yiddish, being the spoken language of the Russian Jews, should be treated as their only national language, while Hebrew was to be treated as a foreign language. Hebrew books and periodicals ceased to be published and were seized from the libraries, although liturgical texts were still published until the 1930s. Despite numerous protests, a policy of suppression of the teaching of Hebrew operated from the 1930s on. Later in the 1980s in the USSR, Hebrew studies reappeared due to people struggling for permission to go to Israel (refuseniks). Several of the teachers were imprisoned, e.g. Yosef Begun, Ephraim Kholmyansky, Yevgeny Korostyshevsky and others responsible for a Hebrew learning network connecting many cities of the USSR.