1.
Letter from Henry Thurstan Holland, Viscount Knutsford to Helen Allingham, February 11, 1912
2.
Letter from Henry Thurstan Holland, Viscount Knutsford to Helen Allingham, February 14, 1912
Letter from Henry Thurstan Holland, Viscount Knutsford to Helen Allingham, February 16, 1912
Note from Henry Thurstan Holland, Viscount Knutsford to Helen Allingham, October 5, 1913
Lord Hood and the defence of Toulon, by J. Holland Rose.
English Public Diplomacy in the Dutch Republic, 1609-1619
Notes and Queries - volume 6, 3rd Series - Page 472
J. C. Smuts : correspondence, 1941
Notes and Queries - volume 5, 3rd Series - Page 55
The Annual Register - volume 9 - Page 162