Marchenko, V. M. Duality in problems of control and observation for linear systems with aftereffect. (Russian. English summary) Zbl 0568.93038 Dokl. Akad. Nauk BSSR 28, 297-300 (1984). A general class of neutral, nonstationary delay-differential systems with distributed delays is considered in this paper. Controllability- observability duality relations for this class of systems are established for different types of controllability and observability. Reviewer: S.H.Żak Cited in 1 Review MSC: 93C30 Control/observation systems governed by functional relations other than differential equations (such as hybrid and switching systems) 34K35 Control problems for functional-differential equations 93C05 Linear systems in control theory 39B52 Functional equations for functions with more general domains and/or ranges 49N15 Duality theory (optimization) 93B05 Controllability 93B07 Observability 93C99 Model systems in control theory Keywords:neutral, nonstationary delay-differential systems; distributed delays; Controllability-observability duality PDF BibTeX XML Cite \textit{V. M. Marchenko}, Dokl. Akad. Nauk BSSR 28, 297--300 (1984; Zbl 0568.93038)