Damayanti, S., S. Yosmar, and N. Afandi. “IMPLEMENTATION OF FUZZY TIME SERIES CHEN FOR FORECASTING INDONESIAN OIL AND GAS IMPORTS VALUE”. BAREKENG: Jurnal Ilmu Matematika Dan Terapan, Vol. 17, no. 2, June 2023, pp. 0685-94, doi:10.30598/barekengvol17iss2pp0685-0694.