Backward Euler type methods for parabolic integro-differential equations in Banach space N. Yu. Bakaev, S. Larsson, V. Thomée (1998) ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique
Boundary value problems for elliptic integro-differential operators. Kazuaki Taira (1996) Mathematische Zeitschrift
Bourgin–Yang-type theorem for a -compact perturbations of closed operators. I: The case of index theories with dimension property. Antonyan, Sergey A., Balanov, Zalman I., Gel'man, Boris D. (2006) Abstract and Applied Analysis