I. – LONG RANGE ORDER – EXTENDED DEFECTS – NON STOICHIOMETRY.ELECTRON MICROSCOPY POTENTIALITIES FOR THE STUDY OF PHASE TRANSITIONS IN SOLIDS J. VAN LANDUYTJ. Phys. Colloques, 38 C7 (1977) C7-5-C7-16DOI: https://doi.org/10.1051/jphyscol:1977702