Crack-Tip Toughness from Vickers Crack-Tip Opening Displacements for Materials with Strongly Rising R-Curves,
Fuenfschilling, S., Fett T., Oberacker R., Hoffmann M. J., Schneider G. A., Becher P. F., and Kruzic J. J.
, Journal of the American Ceramic Society, Jun, Volume 94, Number 6, p.1884-1892, (2011)