Perubahan regulasi sebagai keadaan memaksa terhadap perjanjian: Studi kasus pemutusan perjanjian karena perubahan regulasi (Putusan No.04/PDT.G/2004/PN.BTG) = The change of regulation as force majeure towards contracts: Case study of the annulment of contract due to the change of regulation (Court order (Putusan No.04/PDT.G/2004/PN.BTG) (Fakultas Hukum Universitas Indonesia, 2013)