“Godišnjak Pravnog fakulteta u Banjoj Luci
Neosnovano obogaćenje koje je nastalo radnjom obogaćenog, radnjom trežeg lica ili vanjskog događaja
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Neosnovano obogaćenje može nastati i bez radnje osiromašenog. Ukoliko nastane uslijed radnje obogaćenog, najčešće se radi o upotrebi tuđe stvari u svoju korist. U rimskom pravu i u pojedinim suvremenim usporednim zakonodavstvima takvo neosnovano obogaćenje ispravlja se takozvanim verzionim tužbama (actio de in rem verso), koje su u našem pravu izjednačene sa kondikcionim tužbama, o čemu smo opširnije pisali na početku ovog odjeljka 36.”
( http://www.godisnjakpf.rs/wp-content/uploads/2012/01/trnavci... )


BLACK’S LAW DICTIONARY
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- action de in rem verso
[Latin “action for money applied to (the defendant's) advantage”]
1. Roman & civil law. An action for unjust enrichment, in which the plaintiff must show that an enrichment was bestowed, that the enrichment caused an impoverishment, that there is no justification for the enrichment and impoverishment, and that the plaintiff has no other adequate remedy at law, including no remedy under an express or implied contract.
2. Roman law. An action brought against a paterfamilias or a slave-owner who benefited from the transaction of a child or slave. — Also termed (in both senses) actio de in rem verso.


“FindLaw Legal Dictionary
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actio de in rem verso
[Latin, legal action over something converted to the benefit (of the principal in the law of agency)]
in the civil law of Louisiana
: a doctrine equivalent to the common-law doctrine of unjust enrichment”
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.
( http://dictionary.findlaw.com/definition/actio-de-in-rem-ver... )