3B. Winiger. H. Koziol, B.A. Koch, I(. Zinunermann (eds.). Digest of European Tort Law, Volume 1: Essential Cases on Natural Causation [M]. New York: Springer Wien New York, 2006, p356.
4Jaap Spier and Ohw A. Haazen: Comparative Condusiom on Causation, in J. Spier (Ed.) Unification of Tort Law:. Causation[M], Kluwer Law International, 2001, p146.