Hidden relations for the Smith invariants of a matrix sum Marques de Sá, Eduardo (1990) Portugaliae mathematica
Higher-order linear matrix descriptor differential equations of Apostol-Kolodner type. Kalogeropoulos, Grigoris I., Karageorgos, Athanasios D., Pantelous, Athanasios A. (2009) Electronic Journal of Differential Equations (EJDE) [electronic only]
Hyperreflexive operators on finite dimensional Hilbert spaces Štefan Drahovský, Michal Zajac (1993) Mathematica Bohemica In this paper a complete characterization of hyperreflexive operators on finite dimensional Hilbert spaces is given.