1. The Expanding Universe
2. M. Wegener and P. Øhrstrøm, in Perspectives on Time, Faye et al., eds., (Kluwer Academic, Dordrecht, 1996); the axiomatics has since been simplified and improved.
3. J. R. Lucas, in J. Butterfield, The Arguments of Time (Centenary Volume, British Academy, Oxford University Press, Oxford, 1999); can be downloaded from http://users.ox.ac.uk/~jrlucas/ (II 26).
4. E. A. Milne, Kinematic Relativity (Oxford University Press, 1948/51).