A contemporary review of male breast cancer: current evidence and unanswered questions - Roberto A. Leon-Ferre; Karthik V. Giridhar; Tina J. Hieken; Robert W. Mutter; Fergus J. Couch; Rafael E. Jimenez; John R. Hawse; Judy C. Boughey; Kathryn J. Ruddy (Cancer and Metastasis Reviews, 2018)