Original sentence: A less common version of 'Black Carib' origin is that pre-Columbus African explorers intermingled with the indigenous population (see "They Came Before Columbus" by Ivan Van Sertima).The most common version of how 'Black Caribs' came to be states that in 1635, two Spanish ships carrying slaves to the West Indies from what is now Nigeria were shipwrecked near the island of  Saint Vincent
Edited sentence: (¹) A myth version of 'Black Carib' origin is that pre-Columbus African explorers intermingled with the indigenous population (refer to "They Came Before Columbus" by Ivan Van Sertima).The most common version (¹) of how 'Black Caribs' came to be states that in 1635, two Spanish ships carrying slaves to the West Indies from what is now Nigeria were shipwrecked near the island of  Saint Vincent