"Redonda". BirdLife Data Zone. BirdLife International. 2024. Retrieved 11 September 2024.
books.google.com
Kras, Sara Louise (2008). "The History of Redonda". Antigua and Barbuda. Cultures of the World. Vol. 26. Marshall Cavendish. p. 18. ISBN9780761425700 – via books.google.com. a cableway using baskets was built to transfer the mined phosphate to a pier for shipping