NEUTRON DIFFRACTION STUDY OF MAGNETIC AND CRYSTALLOGRAPHIC PHASE TRANSFORMATION IN MANGANESE ARSENIDE AS A FUNCTION OF TEMPERATURE AND PRESSURE N. N. SIROTA, E. A. VASILEV et G. A. GOVORJ. Phys. Colloques, 32 C1 (1971) C1-987-C1-989DOI: https://doi.org/10.1051/jphyscol:19711351