Citation: Aa. Kornyshev et al., LANDAU THEORY OF A SYSTEM WITH 2 BILINEARLY COUPLED ORDER PARAMETERS IN EXTERNAL-FIELD - EXACT MEAN-FIELD SOLUTION, CRITICAL PROPERTIES ANDISOTHERMAL SUSCEPTIBILITY, Zeitschrift fur Naturforschung. A, A journal of physical sciences, 50(9), 1995, pp. 789-794