1. Bobzien, S. 1986 Die stoische Modallogik. Würzburg: Königshausen + Neumann.
2. Brunschwig, J. and M.C. Nussbaum (eds.) 1993 Passions and Perceptions: Studies in Hellenistic Philosophy of Mind. Cambridge: Cambridge University Press/Paris: Editions de la Maison des Sciences de L’Homme.
3. Burnyeat, M.F. (ed.) 1983 The Skeptical Tradition. Berkeley: University of California Press. Cooper, J.M. 1984 `Plato’s Theory of Human Motivation,’ History of Philosophy Quarterly 1, 3–21.
4. Engberg-Pedersen, T. 1990 The Stoic Theory of Oikeiôsis. Moral Development and Social Interaction in Early Stoic Philosophy. Aarhus: Aarhus University Press.
5. Frede, M. 1983 `Stoics and Skeptics on Clear and Distinct Impressions,’ in: Burnyeat 1983, 65 —93.