Marc Ferro (1997). Colonization. Routledge. p. 1. doi:10.4324/9780203992586. ISBN9780203992586."Colonization is associated with the occupation of a foreign land, with its being brought under cultivation, with the settlement of colonists. If this definition of the term “colony” is used, the phenomenon dates from the Greek period. Likewise we speak of Athenian, then Roman 'imperialism'."
Johnson, S. W.; Leonard, R. S. (1985). "Evolution of Concepts for Lunar Bases". Lunar Bases and Space Activities of the 21st Century. Houston, Texas: Lunar and Planetary Institute. p. 48. Bibcode:1985lbsa.conf...47J.
Tung Dju (T. D.) Lin, cited via James, Barry (February 13, 1992). "On Moon, Concrete Digs?". International Herald Tribune. Archived from the original on November 24, 2006. Retrieved December 24, 2006.
Tung Dju (T. D.) Lin, cited via James, Barry (February 13, 1992). "On Moon, Concrete Digs?". International Herald Tribune. Archived from the original on November 24, 2006. Retrieved December 24, 2006.