A selection from Unsung heroes: fearless men and woman who changed the world. Toby Reynolds & Paul Calver. (2017). Hauppauge, New York: Barron’s. [Singapore, National Library Board – Young Adult Lending English 920.02 REY] and cross references.

[p.28] Harvey Milk – The Editors of Encyclopaedia Britannica. (18 May 2019). Harvey Milk. Encyclopædia Britannica. https://www.britannica.com/biography/Harvey-Milk.

The Official HARVEY MILK Biography. (accessed 19 Nov 2019). http://milkfoundation.org/about/harvey-milk-biography/. Harvey Milk Foundation, P.O. Box 5666, Fort Lauderdale, FL 33310, US.

[p.30] Michael Faraday – BBC. (archived 2014). Michael Faraday (1791-1867). https://www.bbc.co.uk/history/historic_figures/faraday_michael.shtml. UK.

Michael Faraday. (accessed 19 Nov 2019). https://www.famousscientists.org/michael-faraday/.

[p.32] Mary Seacole – National Geographic Kids. The life of Mary Seacole. https://www.natgeokids.com/uk/discover/history/general-history/mary-seacole/. UK.

[p.34] Nikola Tesla – Heather Whipps. (29 May 2014). Nikola Tesla: Biography, Inventions & Quotes. https://www.livescience.com/45950-nikola-tesla-biography.html.