Oyunsurtal E, Tserendorj U. Compared results of agricultural tractors and combine’s engine oil contamination. Mong. J. Agric. Sci. [Internet]. 2021 Feb. 15 [cited 2024 Jul. 22];31(3):160-5. Available from: https://mongoliajol.info/index.php/MJAS/article/view/1550