A. Letter from Indian Prime Minister Jawaharlal Nehru to Chinese Premier Chou En-lai dated 22 March 1959:
"The boundary of Sikkim, a protectorate of India, with the Tibet Region of China was defined in the Anglo-Chinese Convention 1890 and jointly demarcated on the ground in 1895."
B. Letter from Indian Prime Minister Jawaharlal Nehru to Chinese Premier Chou En-lai dated 26 September 1959:
"This Convention of 1890 also defined the boundary between Sikkim and Tibet; and the boundary was later, in 1895, demarcated. There is thus no dispute regarding the boundary of Sikkim with the Tibet region."
C. Note of the Indian Embassy in China to the Chinese Ministry of Foreign Affairs dated 12 February 1960:
"The Chinese Government are aware of the special treaty relations which the Government of India have with Bhutan and Sikkim. In view of this the Government of India welcome the explanations given in the Chinese note relating to the boundaries between Sikkim and Bhutan on the one hand and Tibet on the other. The note states that the boundary between Sikkim and the Tibet region of China has long been formally delimited, and that there is neither any discrepancy on the maps nor any dispute in practice. The Government of India would like to add that this boundary has also been demarcated on the ground."
D. Non-paper provided by the Indian side during the Meeting of the Working Teams of the Special Representatives on China-India Boundary Question on 10 May 2006:
"(e) Both sides agree on the boundary alignment in the Sikkim Sector."