Daniel Siahaan and Zainal Arifin
Asian Journal of Information Technology 8 ( 4 ): 104 - 111 , 2009
Kuntoro Boga Andri, Pudji Santosa and Zainal Arifin
International Journal of Agricultural Research 6 ( 1 ): 58 - 66 , 2011
The Social Sciences 12 ( 6 ): 959 - 966 , 2017