@inproceedings{NeurIPS'23:universal,
    author = {Yu-Hu Yan and Peng Zhao and Zhi-Hua Zhou},
    title = {Universal Online Learning with Gradient Variations: A Multi-layer Online Ensemble Approach},
    booktitle = {Advances in Neural Information Processing Systems 36 (NeurIPS)},
    year = {2023},
    pages = {37682--37715}
}