TY - JOUR T1 - Public transit stop density is associated with walking for exercise among a national sample of older adults AU - Twardzik, Erica AU - Falvey, Jason R. AU - Clarke, Philippa J. AU - Freedman, Vicki A. AU - Schrack, Jennifer A. PY - 2023 DO - 10.1186/s12877-023-04253-x JO - BMC Geriatrics VL - 23 IS - 596 SN - 1471-2318 ER -