Witness History, BBC, 4 de febrero 2020
https://www.bbc.co.uk/programmes/p08
In the 1980s deaf children in Nicaragua invented a completely new sign language of their own. It was a remarkable achievement, which allowed experts a unique insight into how human communication develops. "What we learnt from Nicaragua about language still isn't over," says American linguist Judy Shepard-Kegl, who documented the emergence of what's now known as Nicaraguan Sign Language.