Acre
- articles in 1911 Encyclopædia Britannica:
- "Acre (state)," in Encyclopædia Britannica (11th ed., 1911)
- "Acre (land measure)," in Encyclopædia Britannica (11th ed., 1911)
- "Acre (town)," in Encyclopædia Britannica (11th ed., 1911)
- "Acre," in Easton's Bible Dictionary (1897)
- "Acre," in Catholic Encyclopedia, (ed.) by Charles G. Herbermann and others, New York: The Encyclopaedia Press (1913)
- "Acre," in The New Student's Reference Work, Chicago: F.E. Compton and Co. (1914)