Visitors are seen at the Chinese book section of the Thessaloniki Book Fair in Thessaloniki, Greece, on May 11, 2019. The 16th Thessaloniki Book Fair takes place from May 9 to 12. The Thessaloniki Book Fair, established in 2004, is the most important annual event for the book and the professionals of the field organized in Greece. (Xinhua/Li Xiaopeng)