“Remarks on Zasada efektywności w prawie międzynarodowym [Principle of effectiveness in international law] by Janusz Symonides: On the Anniversary of the Conclusion of the Polish-German Treaties of 1950, 1970 and 1990”, PYIL, vol. 40, pp. 23–38, Nov. 2021, doi: 10.24425/pyil.2021.138427.