1. Allan, K.B. (2000). A commentary on the European Commission’s communication on the precautionary principle. The Law Teacher 34: 215-221.
2. Barnard, C. (2004). The substantive law of the EU. The four freedoms, Oxford University Press, Oxford, UK.
3. C. BarnardThe substantive law of the EU
4. Biszko, K.M. (2011-2012). A house divided: exploring implications of decentralized regulation of genetically modified crops in the European Union. Georgia Journal of International and Comparative Law: 527-554.