Natalia Iwaszczuk, Marta Szyba, Myroslava Mylenka (2019) “USING ALTERNATIVE SOURCES OF METHANE FOR ENERGY AS A METHOD OF ENVIRONMENTAL PROTECTION AND IMPROVEMENT OF ECONOMY CONDITION, ON EXAMPLE OF POLAND”, ACTA INNOVATIONS, 33, pp. 90–99. doi: 10.62441/actainnovations.v33i.202.