American Foundation for the Blind & Orr, A. L. (1992). Vision and aging: Crossroads for service delivery. American Foundation for the Blind.
Dyfyniad Arddull ChicagoAmerican Foundation for the Blind and Alberta L. Orr. Vision and Aging: Crossroads for Service Delivery. New York: American Foundation for the Blind, 1992.
Dyfyniad MLAAmerican Foundation for the Blind and Alberta L. Orr. Vision and Aging: Crossroads for Service Delivery. American Foundation for the Blind, 1992.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.