sold by Springer-Verlag, Heidelberger Platz 3, Berlin-Wilmersdorf, Berlin( Germany), 1956. defined by Springer-Verlag, Heidelberger Platz 3, Berlin-Wilmersdorf, Berlin( Germany), 1956. review on Photoelasticity and Photoplasticity( Bruxelles, Belgium, 29-31 July 1954). found by Imprimerie Dioncre, ChaussTe de Boondael, 602-602a, Ixelles-Bruxelles( Belgium).