Pérez-Ruzafa, A., and C. Marcos. “OBSERVATIONS ON DAILY ACTIVITY AND ECOLOGY OC SORNE SHALLOW-WATER HOLOTHURIANS (<i>ECHINODERMATA: HOLOTHUROIDEA< I>)”. Anales De Biología, no. 12, Oct. 1987, pp. 79-90, https://revistas.um.es/analesbio/article/view/35561.