@inproceedings{zhou_data-efficient_2026,
 author = {Zhou, Hao and Li, Tianhao and Wang, Zhijun and She, Shuaijie and Wu, Linjuan and Wei, Hao-Ran and Yang, Baosong and Chen, Jiajun and Huang, Shujian},
 booktitle = {Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics},
 date = {2026-05-08},
 note = {ACL 2026 paper number: 3069-MAIN},
 title = {A Data-Efficient Path to Multilingual LLMs: Language Expansion via Post-training PARAM$Δ$ Integration into Upcycled MoE},
 url = {https://2026.aclweb.org/program/},
 year = {2026}
}