1. Mandatory norms
2. The Role of Sanctions and Coercion in Understanding Law and Legal Systems, 21 AM;Hans Oberdiek;J. JURIS,1976
3. Some legal philosophers have gone so far as to take these arguments as a given with little need to recite them. See Leslie Green, Law as a Means;Neil Maccormick;THE HART-FULLER DEBATE IN THE TWENTY-FIRST CENTURY,1945
4. On the Functions of Law;Raz;OXFORD ESSAYS IN JURISPRUDENCE,1973