Czaja, S. J. (1990). Human factors research needs of art aging population. Washington, DC: National Academy Press.
2.
Office of Technology Assessment, United States Congress. (1985). Technology and aging in America (OTA-BA-264). Washington. DC: U.S. Government Printing Office.
3.
United States Bureau of the Census. (1988). Statistical abstract of the United States.Washington, DC: U.S. Government Printing Office.