"1921 World Chess Championship". 20 January 2005. Archived from the original on 20 January 2005. பார்க்கப்பட்ட நாள் 21 November 2008. This cites: a report of Lasker's concerns about the location and duration of the match, in New York Evening Post. 15 March 1911; Capablanca's letter of 20 December 1911 to Lasker, stating his objections to Lasker's proposal; Lasker's letter to Capablanca, breaking off negotiations; Lasker's letter of 27 April 1921 to Alberto Ponce of the Havana Chess Club, proposing to resign the 1921 match; and Ponce's reply, accepting the resignation.
"1921 World Chess Championship". 20 January 2005. Archived from the original on 20 January 2005. பார்க்கப்பட்ட நாள் 21 November 2008. This cites: a report of Lasker's concerns about the location and duration of the match, in New York Evening Post. 15 March 1911; Capablanca's letter of 20 December 1911 to Lasker, stating his objections to Lasker's proposal; Lasker's letter to Capablanca, breaking off negotiations; Lasker's letter of 27 April 1921 to Alberto Ponce of the Havana Chess Club, proposing to resign the 1921 match; and Ponce's reply, accepting the resignation.