Penulis Erick Try Putra Benawan David P. E. Saerang Winston Pontoh DOI: https://doi.org/10.32400/gc.13.03.19995.2018 Abstrak Unduhan PDF (English) Diterbitkan 2018-09-30 Terbitan Vol 13 No 03 (2018) Bagian Articles Lisensi Author keep the copyright of the article published in this journal