Hilgert, Joachim. “Maximal Semigroups and Controllability in Products of Lie Groups.” Archiv Math. 49 (1987): 189–95.

Hilgert, Joachim, and K.H. Hofmann. “Invariant Cones in Real Lie Algebras.” In Aspects of Positivity in Functional Analysis, edited by R. Nagel and et al. North Holland, 1986.

Hilgert, Joachim. “The Mayer-Vietoris and the Puppe Sequence in K-Theory for C*-Algebras.” Studia Math. 83 (1986): 97–104.

Hilgert, Joachim, and K.H. Hofmann. “On the Automorphism Group of Cones and Wedges.” Geom. Dedicata 21 (1986): 205–17.

Hilgert, Joachim, and K.H. Hofmann. “On Sophus Lie’s Fundamental Theorem.” J. Funct. Anal. 67 (1986): 1–27.

Hilgert, Joachim, K.H. Hofmann, and J.D. Lawson. “Controllabilty of Systems on Nilpotent Lie Groups.” Beiträge Alg. Geom. 20 (1985): 185–90.

Hilgert, Joachim, and K.H. Hofmann. “Semigroups in Lie Groups, Semialgebras in Lie Algebras.” Trans. AMS 288 (1985): 481–504.

Hilgert, Joachim, and K.H. Hofmann. “Lorentzian Cones in Real Lie Algebras.” Monatshefte Math. 100 (1985): 183–210.

Hilgert, Joachim, and K.H. Hofmann. “Lie Semialgebras Are Real Phenomena.” Math. Ann. 270 (1985): 97–103.

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

Hilgert, Joachim, and K.H. Hofmann. “Lie Theory of Semigroups.” Semigroup Forum 30 (1984): 243–51.