1. First-Stage Design Variations of Partially Reusable Launch Vehicles
2. Sippel, M.; Klevanski, J.; Burkhardt, H.; Eggers, Th.; Bozi , O.; Langholf, Ph.; Rittweger, A: Progress in the Design of a ReusableLaunchVehicleStage, AIAA-2002-5220,September2002
3. Technical Development Perspective of Reusable Booster Stages
4. Sippel, M.; Klevanski, J.: Preliminary Definition of an Aerodynamic Configuration for a Reusable Booster Stage within TightGeometric Constraints,5thEuropeanSymposiumonAerothermodynamicsforSpaceVehicles,November2004