ŁAPKA, Wojciech. “Numerical and Experimental Analysis of Tuning Three Selected Types of Acoustic Helicoidal Resonators With 90-Degree Duct Elbow”. Engineering Transactions 73, no. 4 (December 17, 2025): 701–717. Accessed January 4, 2026. https://et.ippt.pan.pl/index.php/et/article/view/3377.