1. Abi-Saab G (1988) Lex lata and lex ferenda. In: Cassese A, Weiler J (eds) Change and stability in international law-making. Walter de Gruyter, Berlin, pp 76–77
2. Alvarez JE (2005) International organizations as law-makers. Oxford University Press, Oxford
3. Anderson K (2000) The Ottawa convention banning landmines, the role of international non-governmental organizations and the idea of international civil society. EJIL 11:91–120
4. Baxter R (1980) International law in ‘her infinite variety’. ICLQ 29:549–566
5. Besson S (2010) Theorizing the sources of international law. In: Besson S, Tasioulas J (eds) The philosophy of international law. Oxford University Press, Oxford, pp 163–185