We characterize metric spaces X whose hyperspaces 2X (or Bd (X)) of non-empty closed (bounded) subsets, endowed with the Hausdorff metric, are absolute [neighborhood] retracts. © 2007.
Banakh, T., & Voytsitskyy, R. (2007). Characterizing metric spaces whose hyperspaces are absolute neighborhood retracts. Topology and Its Applications, 154(10 SPECIAL ISSUE), 2009–2025. https://doi.org/10.1016/j.topol.2006.02.009