Carrero JC et al., Protection against murine intestinal amoebiasis induced by oral immunization with the 29 kDa antigen of Entamoeba histolytica and cholera toxin. Exp Parasitol. 2010 Nov;126(3):359-65. doi:10.1016/j.exppara.2010.03.007. Epub 2010 Mar 19.