1. 1SpaceFoundationpublication"TheSpaceReport2008"(http://www.thespacereport.org/08executivesummary.pdf)
2. 2Wal-MartAnnualReport,Eleven-YearFinancialSummary,p.26/27URL: http://walmartstores.com/Media/Investors/2007_annual_report.pdf
3. 3NASAASCENTStudyFinalReport,FutronCorporation2003URL: http://www.futron.com/pdf/resource_center/reports/ASCENTFinalReport_V1.pdf
4. 4TheCommercialSpaceTransportationStudy,1994URL:http://www.hq.nasa.gov/webaccess/CommSpaceTrans
5. RLV design issues for future commercial space applications