Ruthenica. Supplementum 4
Early Christianity on the Way from the Varangians to the Greeks / Ed. by Ildar Garipzanov and Oleksiy Tolochko. - K.: Institute of Ukrainian History, 2011. - 148 p. (Ruthenica. Supplementum 4)
http://www.history.org.ua/new.php?litera&id=7070