All publishing houses are owned by the government or the WPK because they are considered an important tool for agitprop. The Workers' Party of Korea Publishing House is the most authoritative among them and publishes all works of Kim Il-sung, ideological education materials and party policy documents. The availability of foreign literature is limited, examples being North Korean editions of Indian, German, Chinese and Russian fairy tales, ''Tales from Shakespeare'', some works of Bertolt Brecht and Erich Kästner, and the ''Harry Potter'' series.