[L-Einstein, 1905a] Albert Einstein, Letter to Conrad Habicht, Princeton Papers, Vol. 5, p. 19, May 18–25, 1905.

[L-Einstein, 1905b] Albert Einstein, Letter to Conrad Habicht, Princeton Papers, Vol. 5, p. 20, June 30–September 22, 1905.

[L-Einstein, 1915] Albert Einstein, Letter to Arnold Sommerfeld, Princeton Papers, Vol. 8, p. 152, November 28, 1915.

[L-Einstein, 1916] Albert Einstein, Letter to Paul Ehrenfest, Princeton Papers, Vol. 8, p. 177, January 17, 1916.

[L-Einstein, 1919a] Albert Einstein, Letter to Pauline Einstein, Princeton Papers, Vol. 9, p. 98, September 27, 1919.

[L-Einstein, 1919b] Albert Einstein, Letter to Max Planck, Princeton Papers, Vol. 9, p. 216, October 23, 1919.

[L-Einstein, 1920] Albert Einstein, Letter to Niels Bohr, Princeton Papers, Vol. 10, p. 151, May 2, 1920.

[L-Einstein, 1924a] Albert Einstein, Letter to Michele Besso, Princeton Papers, Vol. 14, p. 190, January 5, 1924.

[L-Einstein, 1924b] Albert Einstein, Letter to Hans Albert Einstein, Princeton Papers, Vol. 14, p. 221, March 7, 1924.

[L-Einstein, 1924c] Albert Einstein, Letter to Satyendra Nath Bose, Princeton Papers, Vol. 14, p. 266, July 2, 1924.

[L-Einstein, 1939] Albert Einstein, Letter to President Franklin D. Roosevelt, Atomic Archive website, August 2, 1939.

[L-Einstein, 1945] Albert Einstein, Second Letter to President Franklin D. Roosevelt, Atomic Archive website, March 25, 1945.

[L-Einstein, 1952] Albert Einstein, Letter to Abba Eban (Israeli Ambassador to the U.S.), Princeton Papers, AEA 33-288.00, November 18, 1952.

[L-Einstein, 1954] Albert Einstein, Letter to Louis de Broglie, Princeton Papers, AEA 99-041 (Doc. 60), February 15, 1954.

[L-FDR, 1939] President Franklin D. Roosevelt, Reply to Einstein’s Letter, Atomic Archive website, October 19, 1939.

[L-Lorentz, 1919] Hendrik A. Lorentz, Telegram to Albert Einstein about Preliminary Eclipse Results, Princeton Papers, Vol. 9, p. 167, September 22, 1919.

[L-Minkowski, 1907] Hermann Minkowski, Letter to Albert Einstein, Princeton Papers, Vol. 5, p. 44, October 9, 1907.

[L-Noyce, 1968] Robert Noyce, Letter of Resignation from Fairchild Addressed to Sherman Fairchild, Wikimedia Commons website, June 25, 1968. Two pages available separately at: Page 1, Page 2

[L-Planck, 1907a] Max Planck, Letter to Albert Einstein, Princeton Papers, Vol. 5, p. 30, July 6, 1907.

[L-Planck, 1907b] Max Planck, Letter to Albert Einstein, Princeton Papers, Vol. 5, p. 45, November 9, 1907.