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 [Internet]. 2021 Nov. 7 [cited 2026 Mar. 12];40:23-38. Available from: https://czasopisma.inp.pan.pl/index.php/pyil/article/view/2746