D. Tomowski. University of Osnabrück, Germany, (2011)base-search.net (ftunivosnabrueck:oai:osnadocs.ub.uni-osnabrueck.de:urn:nbn:de:gbv:700-201107298216).
D. Thiele. Braunschweig University of Technology, Germany, (2022)base-search.net (ftunivbraunschw:oai:https://leopard.tu-braunschweig.de/:dbbs_mods_00071128).