"Terracotta", p. 341, Delahunty, Andrew, From Bonbon to Cha-cha: Oxford Dictionary of Foreign Words and Phrases, 2008, OUP Oxford, (ISBN0199543690), 9780199543694
Peek, Philip M., and Yankah, African Folklore: An Encyclopedia, 2004, Routledge, (ISBN1135948720), 9781135948726, google books