Source for the art of Nigeria is Isaac Samuel. One of his articles “The history of the Hausa city-states (1100-1804 AD): Politics, Trade and Architecture of an African mercantile culture during west-Africa’s age of empire” includes information on the beautiful patterns of the Hausa embroidery.
SOURCES
Isaac Samuel “The history of the Hausa city-states (1100-1804 AD): Politics, Trade and Architecture of an African mercantile culture during west-Africa’s age of empire.” [article]
Isaac Samuel on Twitter
https://twitter.com/rhaplord/status/1392412935738253313?s=20