(EN) Mary Gladstone Drew, https://archive.org/stream/actongladstonean006182mbp#page/n68/mode/1up, in Acton, Gladstone and others, Londra, NISBET & GO. LTD., 1924, p. 57. URL consultato il 7 febbraio 2015.
«My name for him was the " Flying Dutchman " or the " Fliegende Hollander" He was in some sense associated with wings.»