The spread of metastatic lymph nodes to the mediastinum from left upper lobe cancer: results of superior mediastinal nodal dissection through a median sternotomy. - Sakao,Y.; Miyamoto,H.; Yamazaki,A.; Ou,S.; Shiomi,K.; Sonobe,S.; Sakuraba,M. (Eur J Cardiothorac Surg, 2006)