Hilgert, J. (1987). Maximal Semigroups and Controllability in Products of Lie Groups. Archiv Math., 49, 189–195.

Hilgert, J., &; Hofmann, K. H. (1986). Invariant Cones in Real Lie Algebras. In R. Nagel &; et al. (Eds.), Aspects of Positivity in Functional Analysis. North Holland.

Hilgert, J. (1986). The Mayer-Vietoris and the Puppe Sequence in K-Theory for C*-algebras. Studia Math., 83, 97–104.

Hilgert, J., &; Hofmann, K. H. (1986). On the Automorphism Group of Cones and Wedges. Geom. Dedicata, 21, 205–217.

Hilgert, J., &; Hofmann, K. H. (1986). On Sophus Lie’s Fundamental Theorem. J. Funct. Anal., 67, 1–27.

Hilgert, J., Hofmann, K. H., &; Lawson, J. D. (1985). Controllabilty of Systems on Nilpotent Lie Groups. Beiträge Alg. Geom., 20, 185–190.

Hilgert, J., &; Hofmann, K. H. (1985). Semigroups in Lie Groups, Semialgebras in Lie Algebras. Trans. AMS, 288, 481–504.

Hilgert, J., &; Hofmann, K. H. (1985). Lorentzian Cones in Real Lie Algebras. Monatshefte Math., 100, 183–210.

Hilgert, J., &; Hofmann, K. H. (1985). Lie Semialgebras are Real Phenomena. Math. Ann., 270, 97–103.

Hilgert, J., &; Hofmann, K. H. (1985). Old and New on SL(2). Manuscripta Math., 54, 17–52.

Hilgert, J., &; Hofmann, K. H. (1984). Lie Theory of Semigroups. Semigroup Forum, 30, 243–251.