Nitiyanant, P., V. Pitiguagool, C. Suchato, and R. Varatorn. “Diffuse Pulmonary Neuroendocrine Cell Hyperplasia With Tumorlets and Elevated Serum CEA”. The Bangkok Medical Journal, Vol. 1, no. 1, Feb. 2018, p. 21, doi:10.31524/bkkmedj.2011.02.005.