1. Darby R (1972) NRL Memo Report 2446
2. Fisher MC, Ash RL (1974) NASA TMX-2894
3. Gadd GE (1971) Encyclopedia of Polym Sci and Techn, Vol 15, John Wiley, New York
4. Hoyt JW (1972) Trans ASME, Jl Basic Engg 94:258
5. Landahl, MT (1972) MIT Cambridge/Mass, Dept Aeronaut Astronaut, Report No 1 AFOSR-TR-73-1200