HÖNIG, Vladimír et al. Determination of tractor engine oil change interval based on material properties. In Materials [elektronický zdroj]. ISSN 1996-1944, 2020, vol. 13, issue 23, art. no. 5403 [26 p.] [online]. QK1910347. CCC, WOS, SCOPUS. Dostupné na internete: <https://www.mdpi.com/1996-1944/13/23/5403/htm>