1. The urachus: Its anatomy, histology and development;Begg;J Anat,1930
2. Carcinoma of the urachus;Beck;Br J Urol,1970
3. Argyrophil cells in the urachal epithelium and urachal adenocar-cinoma;Satake;Acta Pathol Jpn,1984
4. Immunohistochemical studies on endocrine cells in urachal remnants;Kamoshida;Byori to Rinsho,1988
5. Expression of the alpha subunit of human chorionic gonadotropin in normal and neoplastic neuroendocrine cells. An immunohistochemical study;Tsutsumi;Acta Pathol Jpn,1989