Ruddon, Raymond W. Cancer biology 4th ed. Oxford: Oxford University Press. 2007: 223 [2015-09-26]. ISBN 9780195175431. (原始内容存档于2014-10-06). 引文格式1维护:冗余文本 (link)
Defining Cancer. National Cancer Institute. [2014-06-10]. (原始内容存档于2014-06-25).
Ruddon, Raymond W. Cancer biology 4th ed. Oxford: Oxford University Press. 2007: 223 [2015-09-26]. ISBN 9780195175431. (原始内容存档于2014-10-06). 引文格式1维护:冗余文本 (link)