1. British Prices and Business Cycles, 1779–1850;Silbering;Review of Economics and Statistics,1923
2. Paul M. Lewis , ed. “Ethnologue: Languages of the World,” 16th edn. Online database, 2009. www.ethnologue.com/.
3. “Merriam-Webster Dictionary Online,” 2011. www.merriam-webster.com/.
4. Abolition and the Re-Deployment of the Slave Fleet, 1807–11;Williams;Journal of Transport History,1973