Stewart CJR, Crook ML, Lacey J, Louwen K. Cytokeratin 19 Expression in Normal Endometrium and in Low-grade Endometrioid Adenocarcinoma of the Endometrium. International Journal of Gynecological Pathology. 2011 Sep;30(5):484–91. doi: 10.1097/pgp.0b013e3182158944.