The IASLC Lung Cancer Staging Project: External Validation of the Revision of the TNM Stage Groupings in the Eighth Edition of the TNM Classification of Lung Cancer - Chansky, Kari; Detterbeck, Frank C; Nicholson, Andrew G; Rusch, Valerie W; Vallieres, Eric; Kennedy, Catherine; Krasnik, Mark; Peake, Michael; Terra, Ricardo Mingarini (Journal of thoracic oncology, 2017)