@article {Kalavrezou-Maxeiner1981, title = {A Church Slavonic graffito in Hagia Sophia in Constantinople}, journal = {Harvard Ukrainian Studies}, volume = {5}, year = {1981}, pages = {5 {\textendash} 11}, url = {http://projects.iq.harvard.edu/huri/files/vv_n1march1981.pdf}, author = {Kalavrezou-Maxeiner, Ioli and Obolensky, Dimitri} }