Wang J, Wang S, Chen R-R, Ji M. Demystifying Why Local Aggregation Helps: Convergence Analysis of Hierarchical SGD. AAAI [Internet]. 2022 Jun. 28 [cited 2026 May 28];36(8):8548-56. Available from: https://ojs.aaai.org/index.php/AAAI/article/view/20832