Yuanhao Ding Yang Liu 0200 Yugang Ji Weigao Wen Qing He 0003 Xiang Ao 0001 SPEAR: A Structure-Preserving Manipulation Method for Graph Backdoor Attacks. 1237-1247 2025 WWW https://doi.org/10.1145/3696410.3714665 conf/www/2025 db/conf/www/www2025.html#DingLJWHA25