1. Łukasiewicz, J. “Philosophische Bemerkungen zu mehrwertigen Systemen des Aussagenkalküls”, Comptes rendus des séances de la Société des Sciences et des Lettres de Varsovie, Cl. III, 23 (1930) 51–77; reprinted as “Philosophical remarks on many-valued systems of propositional logic” in [2], pp. 153–178.
2. Łukasiewicz, J. Selected Works, ed. by L. Borkowski (North-Holland, Amsterdam, and PWN—Polish Scientific Publishers, Warszawa, 1970).
3. Łukasiewicz, J. Die logischen Grundlagen der Wahrscheinlichkeitsrechnung (Acad. der Wiss. Kraków, 1913); reprinted as “Logical foundations of probability theory” in [2], pp. 16–63.
4. Łukasiewicz, J. “O logice trójwartościowej”, Ruch Filozoficzny, 5 (1920) 170–171; reprinted as: “On three-valued logic” in [2], pp. 87–88.
5. Post, E. “Introduction to a general theory of elementary propositions”, Bulletin of the American Mathematical Society, 26 (1920) 437.