“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”. Polish Yearbook of International Law 40 (November 7, 2021): 23–38. Accessed March 12, 2026. https://czasopisma.inp.pan.pl/index.php/pyil/article/view/2746.