K O Bachri, U Khayam, B A Soedjarno, M A Kartawidjaja. 2020. “Improvement of Doernenburg Ratio Method Dissolved-Gas Analysis Using 5-Fold Cross Validation Artificial Neural Network”. International Journal of Advanced Science and Technology 29 (7s), 3338-46. http://sersc.org/journals/index.php/IJAST/article/view/17620.