6J Austin, Lectures on Jurisprudence or the Philosophy of Positive Law, 5th edn (London, John Murray, 1885) 760; P Birks, ‘Equity in the Modern Common Law: An Exercise in Taxonomy’ (1996) 26 University of Western Australia Law Review 1; P Birks, Unjust Enrichment, 2nd edn (Oxford, Clarendon Press, 2005) 20.
7Eg contracts, declarations of trust, gifts, conveyances and wills.
8 Eg torts, equitable wrongs, breach of contract and breach of statutory duty.
9Enrichment at the expense of the claimant that is prima facie reversible due to the presence of an unjust factor: Pavey & Matthews v Paul (1987) 162 CLR 221 (HCA) 256–57 (Deane J); Portman BS v Hamlyn Taylor Neck [1998] 4 All ER 202 (CA) 206 (Millett LJ); Banque Financiere de la Cité v Parc (Battersea) Ltd [1999] 1 AC 221 (HL) 227 (Lord Steyn) 234 (Lord Hoffmann); Roxborough v Rothmans of Pall Mall Australia Ltd [2001] HCA 68, (2001) 208 CLR 516, 568 fn 257 (Kirby J); Rowe v Vale of White Horse DC [2003] EWHC 388 (Admin), [2003] 1 Lloyd’s Rep 418 [11] (Lightman J); Filby v Mortgage Express (No 2) Ltd [2004] EWCA Civ 759, [2004] 2 P&CR DG16 [62] (May LJ); P Birks, An Introduction to the Law of Restitution, revised edn (Oxford, Clarendon Press, 1989) 21; G Virgo, The Principles of the Law of Restitution, 2nd edn (Oxford, Oxford University Press, 2006) 9; A Burrows, The Law of Restitution, 3rd edn (Oxford, Oxford University Press, 2010) 26–27. See, eg Kelly v Solari (1841) 9 M&W 54, 152 ER 24.
10Eg finder’s rights, specification, accession and mixing.
26Cf Virgo, The Principles of the Law of Restitution (2006) (n 9) 4–5.