J. Hilgert and K.-H. Neeb, Eds., Lie-Gruppen und Lie-Algebren. Wiesbaden: Vieweg Verlag, 1991.

J. Hilgert, “Onishchik, A.L., und E.B. Vinberg. Lie Groups and Algebraic Groups (Springer, New York, 1990),” Zentralblatt, vol. 722. 1991.

M. Rösler, “On optimal linear mean estimators for weakly stationary stochastic processes,” in Orthogonal polynomials and their applications (Erice, 1990), 1991, pp. 373–378.

J. Hilgert, “Applications of Lie Semigroups in Analysis,” in The Analytical and Topological Theory of Semigroups, K. H. Hofmann and et al., Eds. Berlin: De Gruyter, 1990.

J. Hilgert and K. H. Hofmann, “On the Causal Structure of Homogeneous Manifolds,” Math. Scand., vol. 67, pp. 119–144, 1990.

M. Dellnitz and B. Werner, “Computational methods for bifurcation problems with symmetries—with special attention to steady state and Hopf bifurcation points,” Journal of Computational and Applied Mathematics, pp. 97–123, 1989.

J. Hilgert and K. H. Hofmann, “Compactly Embedded Cartan Algebras and Invariant Cones in Lie Algebras,” Advances Math., vol. 75, pp. 168–201, 1989.

J. Hilgert, “A Note on Howe’s Oscillator Semigroup,” Ann. Inst. Fourier, vol. 39, pp. 663–688, 1989.

J. Hilgert, K. H. Hofmann, and J. D. Lawson, Eds., Lie Groups, Convex Cones, and Semigroups. Oxford: Oxford University Press, 1989.

J. Hilgert, “Spectrally Ordered Lie Algebras,” in Group Theoretical Methods in Physics, vol. 313, H. D. Doebner and et al., Eds. New York: Springer, 1988.