Signs and symptoms of cancer. What are the signs and symptoms? http://www.cancer.org/cancer/cancerbasics/signs-and-symptoms-of-cancer. updated August 11, 2014. Accessed March 2016.
Chabner BA, Thompson EC. Warning signs of cancer. https://www.merckmanuals.com/home/cancer/overview-of-cancer/warning-signs-of-cancer. Accessed March 2016.
Diagnosis and staging. National Cancer Institute, Accessed March 2016 at https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis