TRAVIS, WD. Neuroendocrine tumors of the lung with proposed criteria for large-cell neuroendocrine carcinoma. An ultrastructural, immunohistohemical and flow cytometric study of 35 cases. Am J Surg Pathol. 1991, 15, 529-553
TRAVIS, WD. World Health Organization Pathology Panel. World Health Organization Histological Typing of Lung and Pleural Tumors. 1999