Keabsahan akta perjanjian kawin dibuat sepanjang perkawinan sebelum adanya putusan Mahkamah Konstitusi Republik Indonesia nomor 69/PUU-XIII/2015 dan akibat hukumnya terhadap pihak ketiga: studi Putusan Pengadilan Tinggi Jawa Tengah nomor 534/PDT/2019/PT SMG = The validity of marriage agreements made during marriage before the verdict of the Constitutional Court of Republic of Indonesia number 69/PUU-XIII/2015 and its legal effect to third party: case study of Central Java's High Court Verdict number 534/PDT/20T/2019/PT SMG