K2NiF4 TYPE OXIDES : THE COMPOUNDS La2-xSrxNiO4-y : CRYSTAL CHEMISTRY AND ELECTRICAL PROPERTIES M. KHAIRY, P. ODIER and J. CHOISNET J. Phys. Colloques, 47 C1 (1986) C1-831-C1-835 DOI: 10.1051/jphyscol:19861127