THE PECULIAR DOMAIN STRUCTURE AND ITS UNUSUAL BEHAVIOUR IN THE β-PHASE OF THE FERROELECTRIC NaH3(SeO3)2 L. A. SHUVALOV, A. A. ASKOCHENSKY and V. A. KIRIKOV J. Phys. Colloques, 33 C2 (1972) C2-163-C2-164 DOI: 10.1051/jphyscol:1972256