1. See Bobbio (1995, 37–66) for a characterisation of theoretical positivism.
2. See Frank (1930; 1949) and Llewelyn (1951).
3. See Hart (1994, Ch. VI) and Raz (1982, Ch. Ill).
4. ee Dworkin (1977, 31–39, 68–71) and Sartorius (1971, 151–160).
5. See Greenawalt (1975, 392–393; 1977, 1004–1007), Dworkin (1977, 84–86), Barak 1989, 192–203) and Sartorius (1971, 158–159).