Trapp, Endres

Kaufmann, Bernd; Trapp, Endres; Mezger, Klaus (2004). The Numerical Age of the Upper Frasnian (Upper Devonian) Kellwasser Horizons: A New U‐Pb Zircon Date from Steinbruch Schmidt (Kellerwald, Germany). Journal of geology, 112(4), pp. 495-501. University of Chicago Press, Journals Division 10.1086/421077

Trapp, Endres; Kaufmann, Bernd; Mezger, Klaus; Korn, Dieter; Weyer, Dieter (2004). Numerical calibration of the Devonian-Carboniferous boundary: Two new U-Pb isotope dilution–thermal ionization mass spectrometry single-zircon ages from Hasselbachtal (Sauerland, Germany). Geology, 32(10), pp. 857-860. Geological Society of America 10.1130/G20644.1