1. Independent Market Study: Commercial Hypersonic Transportation;Mullins,2021
2. The transcost-model for launch vehicle cost estimation and its application to future systems analysis;Koelle;Acta Astronaut.,1984
3. Launch cost analyses for reusable space transportation systems (Sänger II);Koelle;Acta Astronaut.,1989
4. Statistical-analytical Model for Cost Estimation and Economic Optimization of Space Transportation Systems;Koelle,1991
5. Cost estimating of commercial smallsat launch vehicles;Drenthe;Acta Astronaut.,2019