Willem Labuschagne and Johannes Heidema (2011): Leibniz to Lakoff: Language as Instrument for Peace. Junctures 14:51-60.

Britz K, Heidema J, and Labuschagne WA (2009): Semantics for dual preferential entailment. Journal of Philosophical Logic  38(4):433-446.

van Ditmarsch H and Labuschagne WA (2007): My beliefs about your beliefs: a case study in theory of mind and epistemic logic. Synthese  155(2):191-209.

Britz K, Heidema J, and Labuschagne WA (2007): A modal perspective on preferential entailment. Notices of the South African Mathematical Society  38(3). Abstract, see Research Reports for full text.

Heidema J and Labuschagne WA (2006): Hintikka's Alternatives. Junctures : The Journal for Thematic Dialogue: Language  6:35-43.

Labuschagne WA and Heidema J (2005): Natural and artificial cognition: On the proper place of reason. South African Journal of Philosophy 24(2):137-151.

Heidema J and Labuschagne WA (2004): Emancipating agents: Need Schrödinger's cat be let into the Chinese room? Junctures: The Journal for Thematic Dialogue: Body  3:19-30.

van der Poll JA, Kotze P, and Labuschagne WA (2004): Automated support for enterprise information systems. Journal of Universal Computer Science 10(11):1519-1539.

Meyer TA, Heidema J, Labuschagne WA, and Leenen L (2002): Systematic withdrawal. Journal of Philosophical Logic 31(5):415-443.

Meyer TA, Labuschagne WA, and Heidema J (2000): Infobase change: A first approximation. Journal of Logic, Language, and Information 9:353-377.

Meyer TA, Labuschagne WA, and Heidema J (2000): Refined epistemic entrenchment. Journal of Logic, Language, and Information 9:237-259.

van der Poll JA and Labuschagne WA (1999): Heuristics for resolution-based set-theoretic proofs. South African Computer Journal 23:3-17.

Heidema J, Labuschagne WA, Meyer TA and Rosenblatt H (1997): A power-order semantics for nonmonotonic logic. Bulletin of Symbolic Logic 3(1):133-134.

van der Merwe AJ and Labuschagne WA (1997): Theory meets practice: Using Smith's normalisation in complex systems. South African Computer Journal 20:44-48.

Labuschagne WA (1996): Fifty years of artificial intelligence III: Why it's worth the effort. Quantum Dec 1996 29-30.

Labuschagne WA (1996): Fifty years of artificial intelligence II: The engineer's point of view. Quantum Nov 1996 29-30.

Labuschagne WA (1996): Fifty years of artificial intelligence I: Turing's new science. Quantum Oct 1996 23/4.

Halland KJ and Labuschagne WA (1995): A family tree of circumscriptive logics. South African Computer Journal 14:59-63.

Burger IC, Heidema J, Labuschagne WA, Meyer TA and van Wyk B-E (1994): Gradograms — A new aid to cladistic taxonomy. South African Journal for Natural Science and Technology 13(3):135-141.

Labuschagne WA and Miller MG (1994): On using the situation calculus dynamically rather than temporally. South African Computer Journal 12:43-49.

Heidema J, Labuschagne WA, and Pistorius M (1993): Boolean prediction analysis under scrutiny. South African Journal of Psychology 23(1):36-42.

Labuschagne WA and van der Westhuizen PL (1992): Logic programming: Ideal versus practice. South African Computer Journal 8:77-86.

Heidema J and Labuschagne WA (1990): Data-dependence of information. South African Computer Journal 3:39-44.

Labuschagne WA (1986): Mathematical requirements for computer science. Notices of the South African Mathematical Society 18(1):1-7.

Labuschagne WA and van Rooyen HO (1984): On a generalisation of Cayley diagrams. Quaestiones Informaticae 3(2):7-10.

Labuschagne WA (1983): Quantification in terms of the sentential connectives. South African Journal of Philosophy 2:46-48.

Heidema J and Labuschagne WA (1981): Weak completeness of large infinitary l anguages. Journal of Symbolic Logic 46(2):436.