The Triggering Process of an X-class Solar Flare on a Small Quadrupolar Active Region - Qiao Song; Jing-Song Wang; Xiaoxin Zhang; Hechao Chen; Shuhong Yang; Zhenyong Hou; Yijun Hou; Qian Ye; Peng Zhang; Xiuqing Hu; Jinping Dun; Weiguo Zong; et al. (The Astrophysical Journal, 2023)