Aspek Hukum Pembatalan Sertipikat Hak Milik Atas Tanah Karena Akta Jual Beli yang Cacat Hukum (Studi Kasus Putusan No.72/G/2018/PTUN.BDG) = Legal Aspect of Cancellation of Certificate of Land Ownership Due to The Deed of Sale and Purchase is Legally Defected (Case Study of Decision Number 72/G/2018/PTUN.BDG).