Works translated by Trepka include Mleko duchowne dla karmienia i wychowywania chrześcijańskich dziatek, 1556 ("Spiritual milk for nourishment and upbringing of Christian children"),[5] by the Spanish theologian Juan de Valdés, and the Large Catechism of Johannes Brenz.[6]
Trepka served as the Duke's adviser[7] in regard to Polish affairs and in house translator. His son, Jerzy Trepka, was also employed by the Duke.[6]
^ abKrueger, Karl (1992). Psalms and Potatoes: The congregations of the Polish-speaking Protestant Mazurians in East Prussia, Suwalki, Poland, and the United States. University of Michigan (PhD thesis). p. 85.
^Arb, Ingrid (2004). "Hans Daubmann und der Konigsberger Buchdruck im 16. Jahrhundert - Eine Profilskizze". In Walter, Axel (ed.). Königsberger Buch- und Bibliotheksgeschichte. Böhlau Verlag Köln Weimar. p. 108.
^Lueker, E.; Poellot, L.; Jackson, P. (eds.). "Trepka, Eustachy". Christian Cyclopedia. Lutheran Church - Missouri Synod. Retrieved September 16, 2012.