1. Cambridge University Library. Products of the empire. Cinchona: a short history [cited 2015 May 19]. http://www.lib.cam.ac.uk/deptserv/rcs/cinchona.html
2. Honigsbaum M. The fever trail: in search of the cure for malaria. London: Farrar, Straus and Giroux; 2001. p 221−6.
3. Hughes K. Marianne North: the flower huntress [cited 2015 May 19]. http://www.telegraph.co.uk/gardening/5012141/Marianne-North-The-flower-huntress.html
4. Kew Royal Botanical Gardens. The Marianne North Gallery [cited 2015 May 19]. http://www.kew.org/visit-kew-gardens/explore/attractions/marianne-north-gallery
5. Motley C. Cinchona and its product—quinine [cited 2015 May 9]. http://www.ethnoleaflets.com/leaflets/quinine.htm