The earliest works of 19th-century Serbian language reformer Vuk Stefanović Karadžić were published in Vienna by a printing house of Armenian Mechitarists . The Mechitarists also published the works of other Serb authors . In total , they printed 37 books and brochures , including '' The Mountain Wreath '' by Montenegrin Prince-Bishop Petar II Petrović-Njegoš . A '' khachkar '' ( Armenian cross-stone ) , high and made of volcanic rock , stands at the entrance of the Church of the Archangel Gabriel in the Belgrade municipality of Zemun . The monument was erected in 1993 , and it commemorates the Serbian pilots who perished in a plane crash in 1988 while transporting humanitarian aid to Armenia after the country was struck by a catastrophic earthquake
catastrophic earthquake
1988 Armenian earthquake
Armenia–Serbia relations