[1] Bermejo, José María (1981) Graham Greene a través de Leopoldo Durán. Ya 10/7/1981, 43.
[2] Bloch, Michael (1986) Operation Willi: The Nazi Plot to Kidnap the Duke of Windsor / July 1940. New York: Grove Press.
[3] Brennan, Michael G. (2016) Graham Greene: Political Writer. London, Palgrave Macmillan.
[4] Bosco, Mark (2005). Graham Greene's Catholic Imagination. Oxford, Oxford University Press.
[5] Burns, Jimmy (2010) Papa Spy. London: Bloomsbury.
[7] Cloetta, Yvonne (2004) In Search of a Beginning: My Life with Graham Greene. London, Bloomsbury.
[8] Durán, Leopoldo (1982) Testigo español del J'accuse de Graham Greene. Los Domingos de ABC, 4/7/1982, 23–27.
[9] Durán, Leopoldo (1983) La aventura española de Graham Greene: De cómo nació Monseñor Quijote. Ya dominical, 16/1/1983, 4–9.
[10] Durán, Leopoldo (1984) Los ochenta años de Graham Greene. Ya Dominical, 30/9/1984, 4–9.
[11] Durán, Leopoldo (1985) De cómo nació la película Monseñor Quijote. Ya Dominical, 29/9/1985, 4–9.
[12] Durán, Leopoldo (1987) Mis vacaciones con Graham Greene. El País Semanal, 2/8/1987, 24–32.
[13] Durán, Leopoldo (1988a) Anecdotario secreto de mi amigo. ABC Literario, 16/7/1988, vi–vii.
[14] Durán, Leopoldo (1988b) Graham Greene: El gran escritor inglés cumple hoy 84 años. El Faro de Vigo, 2/10/1988, vi–vii.
[15] Durán, Leopoldo (1994) Graham Greene: Friend and Brother. London, HarperCollins.
[16] Durán, Leopoldo (1996) Graham Greene: amigo y hermano. Madrid, Espasa.
[17] Falk, Quentin (1990) Travels in Greeneland: The Cinema of Graham Greene. London, Quartet Books.
[18] González Yuste, Juan and Rafael Conte (1982) " Graham Greene: el inglés impasible", El País Semanal, 10/12/1982: 36–47.
[19] Greene, Graham (1980: 1999) Ways of Escape. London: Vintage.
[20] Greene, Graham (1982: 1983) Monsignor Quixote. London, Penguin.
[21] Greene, Richard ed (2007) Graham Greene: A Life in Letters. New York, W.W. Norton.
[22] Hull, Christopher (2019) Our Man Down in Havana: The Story Behind Graham Greene's Cold War Spy Novel. New York: Pegasus.
[23] Lewis, Jeremy (2010) Shades of Greene: One Generation of an English Family. London: Jonathan Cape.
[24] Mockler, Anthony (1994) Graham Greene: Three Lives. Arbroath, Hunter Mackay.
[25] Molina, César Antonio (1980) Graham Greene. No soy ambiguo desde mi catolicismo, sino desde la vida. Ya, 9/7/1980, 20.
[26] Mosley, Charles ed. (2003) Burke's Peerage, Baronetage & Knightage, 107th edition. Wilmington, Delaware, Burke's Peerage (Genealogical Books).
[27] Pearce, Martin (2016). Spymaster: The Life of Britain's Most Decorated Cold War Spy and Head of MI6, Sir Maurice Oldfield. London: Bantam Press.
[28] Pereda, Rosa María (1980) Graham Greene: Detesto todos los dogmas. El País, 11/7/1980, 24.
[30] Shelden, Michael (1994) Graham Greene: The Enemy Within. London, Random House.
[31] Sherry, Norman (1989) The Life of Graham Greene, vol. 1. London: Jonathan Cape.
[32] Sherry, Norman (2004) The Life of Graham Greene, vol. 3. London, Jonathan Cape.
[33] Villar Flor, Carlos (2015) Graham Greene and Leopoldo Durán: Quixotic Companions across Spain and Portugal. The Grove: Working Papers on English Literature 22, 213–228.
[34] Villar Flor, Carlos (2020) Viajes con mi cura: Las andanzas de Graham Greene por España y Portugal. Granada: Comares/Universidad de La Rioja.
[35] Leopoldo Durán Papers (GUL)
[36] Diaries of Leopoldo Durán (17 notebooks), GUL, box 43.
[37] Hand-written draft of Graham Greene: Friend and Brother (3 versions), GUL, 16:4.
[38] Typed draft of Graham Greene: Friend and Brother, GUL, Box 17.
[39] Letter from Elisabeth Dennys to Leopoldo Durán, 4/3/1987, GUL, 7:12.
[40] Letter from Graham Greene to Leopoldo Durán, 8/1/1976, GUL, 1:13.
[41] Letter from Graham Greene to Leopoldo Durán, 2/3/1976, GUL, 1:14.
[42] Letter from Graham Greene to Leopoldo Durán, 12/4/1976, GUL, 1:15.
[43] Letter (draft) from Leopoldo Durán to Graham Greene, 13/5/1978, GUL, 2:5.
[44] Kenya diaries, 12/9/1953 and 13/9/1953, GUL GG, 1:3.
[45] Letter from Graham Greene to Yvonne Cloetta, 9/6/1975, GUL YPC, 3:5.
[46] Letter from Graham Greene to Yvonne Cloetta, 14/6/1975, GUL YPC, 3:6.
[47] Letter from Graham Greene to Yvonne Cloetta, 21/6/1975, GUL YPC, 3:10.
[48] Letter from Graham Greene to Yvonne Cloetta, 2/7/1975, GUL YPC, 3:7.
[49] Letter from Graham Greene to Yvonne Cloetta, 10/7/1975, GUL YPC, 3:8.
[50] Graham Greene Collection, Burns Library, Boston College (BC)
[51] Letter from Graham Greene to Leopoldo Durán, 7/4/1975, BC, 17/28.
[52] Letter from Graham Greene to Leopoldo Durán, 1/12/1975, BC, 17/28.
[53] Letter from Graham Greene to Leopoldo Durán, 14/3/1983, BC, 17/36.
[54] Letter from Graham Greene to Maria Newall, 17/1/1976, BC, 29/38.
[55] Letter from Graham Greene to Maria Newall, 11/6/1976, BC, 29/38.
[56] Letter from Graham Greene to Maria Newall, 8/7/1976, BC, 29/38.
[57] Letter from Leopoldo Durán to Graham Greene, 21/4/1975, BC, 17/28.
[58] Letter from Leopoldo Durán to Graham Greene, 13/5/1978, BC, 17/31.
[59] Letter from Leopoldo Durán to Graham Greene, 2/1/1981, BC, 17/34.
[60] Letter from Leopoldo Durán to Graham Greene, 18/3/1982, BC, 17/35.
[61] Letter from Maria Newall to Graham Greene, 18/9/1975, BC, 29/38.
[62] Letter from Maria Newall to Graham Greene, 26/10/1975, BC, 29/38.
[63] Letter from Maria Newall to Graham Greene, 3/12/1975, BC, 29/38.
[64] Letter from Graham Greene to Dermot Mills, SJ, 16/12/1965, Bodleian Library, MSS Eng c7227-34.
[65] File " Anne-Marie Comert", National Archives, Kew, HS 9/339/2.
[66] Shakespeare, Nicholas, interview in Berkhamstead, 30/9/2013.
[67] Verde, Aurelio, interview in Málaga, 24/6/2017.