1. Balzer, W., C. U. Moulines, and J. D. Sneed: 1987,An Architectonic for Science, The Structuralist Program, D. Reidel, Dordrecht.
2. DiSalle, R.: 1992, ?Einstein, Newton and the Empirical Foundations of Spacetime Geometry?,International Studies in the Philosophy of Science 6(3), 181?9.
3. Earman, J.: 1989,World Enough and Space-Time, Absolute versus Relational Theories of Space and Time, MIT Press, Cambridge, MA.
4. Ehlers, J.: 1973, ?The Nature and Structure of Spacetime?, in J. Mehra (Ed.),The Physicist's Conception of Nature, D. Reidel, Dordrecht.
5. Friedman, M.: 1983,The Foundations of Space-Time Theories, Princeton University Press, Princeton.