Astor, John Jacob
- articles in The American Cyclopædia (1879):
- "Astor, John Jacob," in The American Cyclopædia (1879)
- articles in Encyclopædia Britannica, Ninth Edition
- "Astor, John Jacob," in Encyclopædia Britannica, Ninth Edition (1875–1889)
- articles in The Encyclopedia Americana (1920)
- "Astor, John Jacob (capitalist)," in The Encyclopedia Americana, New York: The Encyclopedia Americana Corporation (1920)
- "Astor, John Jacob (inventor)," in The Encyclopedia Americana, New York: The Encyclopedia Americana Corporation (1920)
- "Astor, John Jacob (merchant)," in The Encyclopedia Americana, New York: The Encyclopedia Americana Corporation (1920)
- articles in The New International Encyclopædia
- "Astor, John Jacob (capitalist)," in The New International Encyclopædia, New York: Dodd, Mead and Co. (1905)
- "Astor, John Jacob (merchant)," in The New International Encyclopædia, New York: Dodd, Mead and Co. (1905)
- articles in Collier's New Encyclopedia (1921)
- "Astor, John Jacob (capitalist)," in Collier's New Encyclopedia, New York: P. F. Collier & Son Co. (1921)
- "Astor, John Jacob (merchant)," in Collier's New Encyclopedia, New York: P. F. Collier & Son Co. (1921)
- articles in 1911 Encyclopædia Britannica
- "Astor, John Jacob," in Encyclopædia Britannica (11th ed., 1911)
- articles in The New Student's Reference Work
- "Astor, John Jacob," in The New Student's Reference Work, Chicago: F.E. Compton and Co. (1914)
- articles in Appletons' Cyclopædia of American Biography
- "Astor, John Jacob," in Appletons' Cyclopædia of American Biography, New York: D. Appleton and Co. (1891)
- "Astor, John Jacob (capitalist)," in Appletons' Cyclopædia of American Biography, New York: D. Appleton and Co. (1891)