1. J. A. Schouten,Ricci-Calculus, 2nd edn. (Springer, Berlin, 1954).
2. R. W. Lardner,Arch. Mech. (Poland)25, 911 (1973).
3. S. Weinberg,Gravitation and Cosmology (Wiley, New York, 1972).
4. J. B. Davies,E.O.S., Trans. Am. Geophys. Union 61, 1051 (1980).
5. F. R. N. Nabarro,Theory of Crystal Dislocations (Clarendon Press, Oxford, 1967), p. 51.