Röhl, J.C.G.; Warren, M.; Hunt, D. (1998). Purple Secret. Bantam Press.
doi.org
dx.doi.org
Peters TJ, Wilkinson D (2010). "King George III and porphyria: a clinical re-examination of the historical evidence". History of Psychiatry21 (81 Pt 1): 3–19. doi:10.1177/0957154X09102616. பப்மெட்:21877427.
nih.gov
ncbi.nlm.nih.gov
Peters TJ, Wilkinson D (2010). "King George III and porphyria: a clinical re-examination of the historical evidence". History of Psychiatry21 (81 Pt 1): 3–19. doi:10.1177/0957154X09102616. பப்மெட்:21877427.
royal.uk
"King George IV". Official website of the British monarchy. பார்க்கப்பட்ட நாள் 18 April 2016.