* Breve diccionario etimológico de la lengua castellana, Joan Corominas, Madrid, Gredos, 1961
* Breve diccionario etimológico de la lengua castellana, Joan Corominas, Madrid, Gredos, 1961
* [https://www.britannica.com/science/cobalt-chemical-element Cobalt, Encyclopædia Britannica Online]
* [https://www.britannica.com/science/cobalt-chemical-element Cobalt, Encyclopædia Britannica Online]
+
* Henderson, Julian (2000). «Glass». The Science and Archaeology of Materials: An Investigation of Inorganic Materials. Routledge. p. 60. ISBN 978-0-415-19933-9
+
* [https://archive.org/details/lehrbuchderanorg00wibe Holleman, A. F., Wiberg, E., Wiberg, N. (2007). «Cobalt». Lehrbuch der Anorganischen Chemie, 102nd ed. (en alemán). de Gruyter. pp. 1146–1152. ISBN 978-3-11-017770-1]