C. Neumann


, 1976a, On the definition of the equality of successive intervals of time, in M. Čapek (ed.), The concepts of space and time, Dordrecht, Springer, pp. 233-234.

, 1976b, On the necessity of the absolute frame of reference, in M. Čapek (ed.), The concepts of space and time, Dordrecht, Springer, pp. 125-127.