The effect of urban air pollutants in Germany: eco-efficiency analysis through fractional regression models applied after DEA and SFA efficiency predictions Victor Moutinho Mara Madaleno Pedro Macedo Publication Journal: Sustainable Cities and Society Year of Publication: 2020 Identifiers ISSN: 2210-6707 Other Numbers: 2-s2.0-85083492659 Alternative titles DOIGoogle ScholarBibTeXRIS Locators