For details on mammograms, go to:
http://www.cancer.gov/cancertopics/factsheet/detection/mammograms

To learn more about the controversy surrounding mammograms, go to:
http://www.nejm.org/doi/full/10.1056/NEJMoa1206809
http://well.blogs.nytimes.com/2012/11/28/ignoring-the-science-on-mammograms/

http://articles.latimes.com/2009/aug/17/health/he-breast-overdiagnosis17

For an article on the Effect of three decades of screening mammography on breast-cancer incidence, go to:
http://www.ncbi.nlm.nih.gov/pubmed?term=N%20Engl%20J%20Med%20367%3A1998-2005%2C%202012