1. Dominic Wilson and Roopa Purushothaman, Dreaming with the BRICs: the path to 2050. in: GOLDMAN sachs global economics Paper no: 99, p. 2.
2. NASA, The Vision for Space Exploration. Washington, DC, February 2004.
3. Alain Dupas. Dual Space Dominance: The Hidden Agenda Behind George W. Bush New Space Vision, Paris, 2004.
4. NASA. The Vision for Space Exploration. Washington, DC, February 2004, preface pages.
5. NYTimes, Steven Lee Myers: Europe: Russia: payment wanted for US Space trips. 08-05.2004, Section 1, Column 5, p. 8.