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

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

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

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

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

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

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

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

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

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