1. Abelson, R. (1967). Definition. In P. Edwards (Ed.), The encyclopedia of philosophy (Vol. 2, pp. 314–324). New York: Macmillan & The Free Press.
2. Ajdukiewicz, K. (1928). Definicja. [Parts published in Jȩzyk i Poznanie. Tom I. Wybór Pism z Lat 1920–1939, Warszawa 1960 and 1985, pp. 44–61].
3. Ajdukiewicz, K. (1936). Die Definitionen. In Actes du I Congrés International de Philosophie Scientifique, pp. 1–6. Hermann, Paris. (The Polish version translated by Franciszek Zeidler published in Jȩzyk i Poznanie. Tom I. Wybór Pism z Lat 1920–1939, Warszawa 1960 and 1985, pp. 243–248).
4. Ajdukiewicz, K. (1960). Przedmowa. In Jȩzyk i Poznanie. Tom I. Wybór Pism z Lat 1920–1939, pp. v-viii. PWN, Warszawa (Introduction to the collection).
5. Ajdukiewicz, K. (1958). Three concepts of definition. Logique et Analyse, 1(3–4), 115–126.