Purba, Elidawaty and Purba, Bonaraja and Khairad, Fastabiqul and Damanik, Darwin and Siagian, Valentine and Ginting, Ari Mulianta and Silitonga, Hery Pandapotan and Fitrianna, Nurma and SN, Arfandi and Ernanda, Revi (2021) Metode Penelitian Ekonomi. Yayasan Kita Menulis, Medan.