.   Robertson, Geoffrey (2005). The Tyrannicide Brief: The story of the man who sent Charles I to the scaffold . Chatto & Windus / Vintage . ISBN   978-0-09-945919-4 .   Robertson, Geoffrey (23 April 2011). "My hero: John Cooke" . The Guardian . http://www.guardian.co.uk/books/2011/apr/23/john-cooke-my-hero-geoffrey-robertson .   [ edit ]