Rumbewas, Martha Ilona, Buraerah A. Hakim, and A. L Rantetampang A. L Rantetampang. 2015. “Factors Affecting of Pure K1”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 24 (7):50-59. https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/5043.