1. For instance: J. Lighthill, 1986, The Recently Recognized Failure of Predictability in Newtonian Dynamics, Proc. Roy. Soc. A407, 35–50
2. First presented in H.C. Van de Hulst, 1983, “Comments”, in The First 25 Years in Space, A.A. Needell, ed., 107–114, Washington D.C., Smithsonian Institution Press
3. H. Friedman, 1965, The Next 20 Years of Space Science, Astronautics and Aeronautics, 3, 40–47
4. P.R. Escobal, Methods of Orbit Determination, 1965, reviewed by H.C. Van de Hulst in Space Science Reviews, 6, 414, 1966
5. H. Van de Wall, 1975, Falsifications in Art