Some aspects of the Vocal Music of Transylvanian German Ethnic (Saxonian) Composers : Rudolf Lassel, Paul Richter and Hans Peter Türk - Oltean, Tatiana (. Musical Romania and the neighbouring cultures. - Frankfurt, M. : PL Acad. Research, 2014. - 368 S.. - Ill., Noten. - ISBN 3-631-64880-4, 2014)