• Statute of the International Court of Justice (see Art. 38)
  [www.icj-cij.org/icjwww/ibasicdocuments/ibasictext/ibasicstatute.htm#CHAPTER_I]

• Permanent Court of International Justice, judgement of 7 September 1927, Lotus
  [www.icj-cij.org/icjwww/ibasicdocuments/ibasictext/ibasicstatute.htm#CHAPTER_I]

• International Court of Justice, summary of the judgement delivered in The North Sea Continental Shelf cases (23 February 1969)
  [www.icj-cij.org/icjwww/idecisions/isummaries/icssummary690220.htm]
• International Court of Justice, judgement delivered in the Nicaragua case (27 June 1986)
  [www.icj-cij.org/icjwww/icases/inus/inusframe.htm].

• Martens clause, preamble of the 1899 Hague Convention II
  [www.icrc.org/ihl.nsf/b0d5f4c1f4b8102041256739003e6366/
  9fe084cdac63d10fc12563cd00515c4d?OpenDocument]
• International Court of Justice, Advisory Opinion in Legality of the Threat or Use of Nuclear Weapons, 8 July 1996
  [www.icj-cij.org/icjwww/icases/iunan/iunanframe.htm]
• International Tribunal for the former Yugoslavia, judgement of 14 January 2000, caso Kupreski ć,"see paragraphs 521-536
  [www.un.org/icty/kupreskic/trialc2/judgement/index.htm]

Persistent objector theory

• US Restatement of the Law Third (see I, 18, 26 (§102d) and 32 (note 2)
  [www.kentlaw.edu/classes/bbrown/IntlLawF2004/Course%20Documents/Reinstatement_Sources.rtf]

• International Court of Justice, summary of the judgement of 12 April 1960 in Right of Passage over Indian territory
  [www.icj-cij.org/icjwww/idecisions/isummaries/ipoisummary600412.htm]

• Role of the International Law Commission
  [www.un.org/law/ilc/introfra.htm]
• Relationship between codification treaties and customary international law: International Court of Justice, §70 of the ICJ Advisory Opinion in Legality of the Threat or Use of Force
  [www.icj-cij.org/icjwww/icases/iunan/iunanframe.htm]