Jurdjevic, V.; Kupka, I. A. K. Linear systems with degenerate quadratic costs. (English) Zbl 0825.49028 C. R. Math. Acad. Sci., Soc. R. Can. 10, No. 2, 101-106 (1988). Cited in 1 Document MSC: 49K15 Optimality conditions for problems involving ordinary differential equations 93C05 Linear systems in control theory 37J99 Dynamical aspects of finite-dimensional Hamiltonian and Lagrangian systems 93C15 Control/observation systems governed by ordinary differential equations PDFBibTeX XMLCite \textit{V. Jurdjevic} and \textit{I. A. K. Kupka}, C. R. Math. Acad. Sci., Soc. R. Can. 10, No. 2, 101--106 (1988; Zbl 0825.49028)