BoydB.TonkinBoydB., Sophia: Princess, Suffragette, Revolutionary by Anita Anand, book [online], The Independent, 8 stycznia 2015 [dostęp 2023-04-04], Cytat: ...the platonic love-affair that yoked Victoria to the dispossessed Maharajah Duleep Singh, "so handsome and charming"...(ang.).
AnitaA.AnandAnitaA., Sophia : princess, suffragette, revolutionary, New York, NY: Bloomsbury Publishing USA, 13 stycznia 2015, s. 11, ISBN 978-1-63286-082-8, OCLC899212149.