Markham entry from Wikipedia.
Markham entry from the Dictionary of National Biography.
The Life of Sir Clements R. Markham by Albert Markham (London: John Murray, 1917).
Introduction to Antarctic Obsession; A personal narrative of the origins of the British National Antarctic Expedition 1901-1904 by Sir Clements Markham, edited and introduced by Clive Holland. Alburgh, Harleston, Norfolk: Bluntisham Books - Erskine Press, 1986, Pages ix-xxiii. Appears with the permission of the publisher.
Ann Savours wrote 'Clements Markham; The Longest Serving Officer, Most Prolific Editor' which appears in Compassing the Vaste Globe of the Earth (Studies in the History of the Hakluyt Society 1846-1996), edited by R.C. Bridges and P.E.H. Hair (London: The Hakluyt Society, 1996, Series II, Volume 183). Pages 181-83; 187-88. This cannot be included here but is worth seeking out.
From Greenland's Icy Mountains, by Ann Savours (History Today, Volume 51 (3), March 2001). Pages 44-51. Appears with the permission of the author.
Markham's Mastery Chapter VII, Record of the Royal Geographical Society, by Hugh Robert Mill (London: Royal Geographical Society, 1930).
A chapter from Markham Memorials… Being a new edition, with many additions and corrections, of the 'History of the Markham Family,' by the Rev. David F. Markham ... Heraldically illustrated by Mabel Markham. London: Spottiswoode & Co., 1913. 2 volumes. Provided by Mr Victor Markham.
Markham's obituary that appeared in 'The Geographical Journal', Vol. XLVII, No. 3, March 1916.