Chen, Qianxu, and Xin Yang. “A Study of Damage Mode Recognition of Polypropylene Fiber-Reinforced Recycled Aggregate Concrete Based on Principal Components of Acoustic Emission Signals”. Archives of Acoustics (March 25, 2026). Accessed June 2, 2026. http://acoustics.ippt.gov.pl/index.php/aa/article/view/4407.