1. van Inwagen, P.: An Essay on Free Will. Oxford University Press, Oxford (1983)
2. Goldman, A.: Action and free will. In: Osherson, D.N., Kosslynand, S.M., Hollerbach, J.M. (eds.) An Invitation to Cognitive Science. Visual Cognition and Action, vol. 2, pp. 317–340. MIT Press, Cambridge (1990)
3. Walter, H.: Neurophilosophy of Free Will: From Libertarian Illusions to a Concept of Natural Autonomy (translated by C. Klohr). MIT Press, Cambridge (2001)
4. Original German version: Neurophilosophie der Willensfreiheit, 2nd edn. Mentis Verlag, Paderborn (1999)
5. Brembs, B.: Toward a scientific concept of free will as a biological trait: spontaneous actions and decision-making in invertebrates. Proc. R. Soc. B 278, 930–939 (2011)