COLOUR CENTRES IN DOPED ALKALI HALIDES.THE ROLE OF OXYGEN AND TITANIUM IN THE LUMINESCENCE OF LiF : Mg : Ti M. C. WINTERSGILL, P. D. TOWNSEND et F. CUSSO-PEREZJ. Phys. Colloques, 37 C7 (1976) C7-123-C7-126DOI: https://doi.org/10.1051/jphyscol:1976724