Portuguese stock market returns and oil price variations APPLIED ECONOMICS LETTERS Journal Article Sebastião Messias Marques Margarida Catalão-Lopes Publication Year of Publication: 2015 Identifiers ISSN: 1466-4291 Other Numbers: WOS:000349800400002 Locators URL Array DOI: 10.1080/13504851.2014.952888 Sustainable Development Goals