Encyclopedia and dictionary articles
- Cambridge Dictionary of Philosophy (ed. R. Audi, Cambridge 1995)
- ‘Epicureanism’, ‘Stoicism’, ‘Hellenistic Philosophy’
- Oxford Classical Dictionary (3rd edition, 1996)
- ‘Academy’, ‘Anaxarchus’, ‘Crantor’, ‘Dialectic’, ‘Diodorus’, ‘Eubulides’, ‘Hippobotus’, ‘Megarian school’, ‘Nausiphanes’, ‘Nicias’, ‘Philo’, ‘Polemon’, ‘Stilpon’
- The Encyclopedia of Classical Philosophy (ed. D.J. Zeyl, Westport, Ct. 1997)
- ‘Anonymous commentator on the Theaetetus’, ‘Colotes’, ‘Hermarchus’, ‘Metrodorus of Lampsacus’, ‘Polyaenus’
- The Routledge Encyclopedia of Philosophy (ed. E. Craig, London, 1998)
- ‘Ancient philosophy’, ‘Atomism, ancient’, ‘Arete’, ‘Ariston of Chios’, ‘Chrysippus’, ’Cleanthes, ‘Epicurus’, ‘Epicureanism’, ‘Dialectical school’, ‘Hellenistic philosophy’, ‘Megarian school’, ‘Parmenides’, ‘Presocratic philosophy’, ‘Melissus’, ‘Stoicism’, ‘Zeno of Citium’
- The Cambridge Dictionary of Classical Civilisation (ed. G. Shipley et al., Cambridge, 2006)
- ‘Matter’, ‘Philosophical schools’, ‘Philosophy, Greek’, ‘Sceptics’, ‘Stoicism’
- The Classics of Western Philosophy, ed. J.J.E. Gracia, G.M. Reichberg, B.N. Schumacher (Oxford, 2003)
- ‘Lucretius, De Rerum Natura’
- The Stanford Encyclopedia of Philosophy, ed. E.N. Zalta
- ‘Lucretius’ (2004)
- ‘Plato, Cratylus’ (2006)
- The Handbook for Mereology (Munich, forthcoming)
- ‘Ancient Greek Atomism’
- The Oxford Encyclopedia of Ancient Greece and Rome (Oxford, forthcoming)
- ‘Teleology’