The Kluvanek-Kantorovitz characterization of scalar operators in locally convex spaces. Smith, William V. (1982) International Journal of Mathematics and Mathematical Sciences
The single-valued extension property for sums and products of commuting operators T. L. Miller, Michael M. Neumann (2002) Czechoslovak Mathematical Journal It is shown that the sum and the product of two commuting Banach space operators with Dunford’s property ( C ) have the single-valued extension property.
Théorie spectrale H. Buchwalter, D. Tarral (1982) Publications du Département de mathématiques (Lyon)