1. Aday, L. A. (2001). At risk in America: The health and health care needs of vulnerable populations in the United States. San Francisco, CA: Jossey-Bass.
2. Adler, N. E., Boyce, T., Chesney, M. A., Cohen, S., et al. (1994). Socioeconomic status and health: the challenge of the gradient. American Psychologist, 49, 15–24.
3. American Cancer Society. (2007). Breast cancer facts and figures 2007–2008. Retrieved on October 9, 2013, from http://www.cancer.org/research/cancerfactsstatistics/ .
4. American Cancer Society. (2013a). Cancer facts and figures 2013. Retrieved on October 9, 2013, from http://www.cancer.org/research/cancerfactsstatistics/cancerfactsfigures2013/index .
5. American Cancer Society. (2013b). Breast cancer facts and figures 2013–2014. Retrieved on October 9, 2013, from http://www.cancer.org/research/cancerfactsstatistics/ .