Vergara, W.; Rodríguez, A. Histology of the Digestive Tract of Three Species of Sea Cucumber Isostichopus Badionotus, Stichopus Sp. And Stichopus Hermanni (Aspidochirotida: Stichopodidae). Rev. Biol. Trop. 2015, 63, 1021–1033.