ANISOTROPIC SHUBIN OPERATORS AND EIGENFUNCTION EXPANSIONS IN GELFAND-SHILOV SPACES Article Cappiello M., Gramchev T., Pilipovic S., Rodino L. Journal d'Analyse Mathematique. Springer New York LLC. Vol. 138. 2019. P. 857-870
INVARIANT CONVEX BODIES FOR STRONGLY ELLIPTIC SYSTEMS Article Kresin G., Maz′ya V. Journal d'Analyse Mathematique. Springer New York LLC. Vol. 135. 2018. P. 203-224