1. Civil Needs Data Base (CNDB) Version 3.0, Code M;NASA,1988
2. Space transportation architecture and technologies;Austin,1987
3. Space launch systems—current United States plans and the next logical steps through 2000;Branscome,1987
4. Advanced launch system (ALS) program status and plans;Wormington,1988
5. Orbital transfer vehicle;NASA Fact Sheet,1988