@misc{theopold_doublecavity_etalon_1993, 
author={Theopold, F. A.,Weitkamp, C.,Michaelis, W.},
title={Double-Cavity etalon in the near infrared},
year={1993},
howpublished = {journal article,GKSS report},
note = {Online available at: \url{} (DOI). Theopold, F.; Weitkamp, C.; Michaelis, W.: Double-Cavity etalon in the near infrared. Optics Letters. 1993. vol. 18, no. 3, 253-254.}}