Zacny, Kris; Cohen, Marc M.; James, Warren W.; Hilscher, Brent (10 de septiembre de 2013). «Asteroid Mining». AIAA SPACE 2013 Conference and Exposition(en inglés estadounidense) (American Institute of Aeronautics and Astronautics). ISBN9781624102394. doi:10.2514/6.2013-5304. Consultado el 3 de agosto de 2018.
Zacny, Kris; Cohen, Marc M.; James, Warren W.; Hilscher, Brent (10 de septiembre de 2013). «Asteroid Mining». AIAA SPACE 2013 Conference and Exposition(en inglés estadounidense) (American Institute of Aeronautics and Astronautics). ISBN9781624102394. doi:10.2514/6.2013-5304. Consultado el 3 de agosto de 2018.
Mill, John Stuart (1848) "Of the Stationary State," Book IV, Chapter VI in Principles of Political Economy: With Some of Their Applications to Social Philosophy, J.W. Parker, London, England. Consultado el 2 de agosto de 2010. «The increase of wealth is not boundless. The end of growth leads to a stationary state. The stationary state of capital and wealth… would be a very considerable improvement on our present condition. […] ...a stationary condition of capital and population implies no stationary state of human improvement. There would be as much scope as ever for all kinds of mental culture, and moral and social progress; as much room for improving the art of living, and much more likelihood of it being improved, when minds ceased to be engrossed by the art of getting on.»