Jos Schaeken, PhD (1962), Leiden University, is Professor of Slavic and Baltic languages and cultural history at that university. He has published several monographs and many articles in the field of Slavic philology, including Old Church Slavonic and Old Russian.
Jos Schaeken has produced a subtle, impressively thorough (despite its brevity) and up-to-date guide to an important, intriguing and deceptively complex set of sources. His book is a very welcome addition to the lamentably limited English-language bibliography of the subject. -Simon Franklin, Clare College, University of Cambridge in Journal of Historical Sociolinguistics, 2019 Le livre de J. Schaeken est une belle et multifacette representation de tout le corpus des documents sur ecorce de bouleau. -Timofey V. Guimon in Cahiers de civilisation Medievale, 2019