Check-lists
* List of countries might not be complete
Links and literature
[1] 
Domínguez-Alonso P. (1999): Sistematica, Anatomia, Estructura y Función de Ctenocystoidea (Echinodermata Carpoidea del Paleozoico inferior), PhD thesis. Universidad Complutense de Madrid. 538 p. [as Gilcidia viviannae Domínguez-Alonso, 1999]
Domínguez-Alonso P. (1999): Sistematica, Anatomia, Estructura y Función de Ctenocystoidea (Echinodermata Carpoidea del Paleozoico inferior), PhD thesis. Universidad Complutense de Madrid. 538 p. [as Gilcidia viviannae Domínguez-Alonso, 1999]