According to bibliographer, scholar, and librarian Richard Bleiler, biographical accounts of Campbell's life tend to be sparse and are often contradictory; repeating content that is in error.
[1] It is likely that the family relocated to England to seek expert medical care for Phyllis's father who had suffered a bad fall that had damaged an artery leading to the development of a debilitating heart condition.
[2] Letters from John Campbell, 9th Duke of Argyll were found on his body, and the event was widely reported in the international press due to the family connection to the Scottish peer; including The New York Times.
[7] Part of Back to the Front recounts tales of French soldiers having religious visions on the battlefield, and because of this the memoir is considered a parallel work to Arthur Machen's short story "The Bowmen" which inspired the legend of the Angels of Mons.
[9] The White Hen was adapted into a 1921 silent film starring Mary Glynne, Leslie Faber, Pat Somerset, and Cecil Humphreys.