Hua Zhu, Xiuping Li, and Song Jia. “Compact and Coding Expandable Chipless RFID Tag With Bending Arms”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 34, no. 09, Sept. 2019, pp. 1359-65, https://journals.riverpublishers.com/index.php/ACES/article/view/8237.