1. ORE D117 RP.5 Utrecht October 1974, “Optimum adaptation of the conventional track to future traffic - Deformation of Railway Ballast under Repeated Loading (Triaxial Tests).”
2. ORE D71 RP.8 Utrecht March 1968, “Stresses in the formation (Static Tests)”.
3. ORE D71 RP.11 Utrecht October 1970, “Stresses in the ballast and the formation (Dynamic Conditions)”.
4. ORE D117 RP4. Utrecht April 1974, “Rheological Properties of the Track.”
5. ORE D117 RP6 (To be published Utrecht April 1975) “Rheological Properties of the track (Continued)”.