ARENS-MICHAEL ENVELOPES, HOMOLOGICAL EPIMORPHISMS, AND RELATIVELY QUASIFREE ALGEBRAS Article Pirkovskiĭ A.Yu., Drensky Vesselin Trudy Moskovskogo Matematicheskogo Obshchestva. 2008.
ON THE FREDHOLM AND UNIQUE SOLVABILITY OF NONLOCAL ELLIPTIC PROBLEMS IN MULTIDIMENSIONAL DOMAINS Article Gurevich P.L., Skubachevskiĭ A.L., Volpert Vitaly A. Trudy Moskovskogo Matematicheskogo Obshchestva. 2007.