@misc{appel_an_electron_1991, 
author={Appel, F.},
title={An electron microscope study of the origin of latent hardening in NaCl},
year={1991},
howpublished = {journal article},
note = {Online available at: \url{} (DOI). Appel, F.: An electron microscope study of the origin of latent hardening in NaCl. Philosophical Magazine  A. 1991. vol. 63, 71-85.}}