Random walks and market efficiency tests: evidence on US, Chinese and European capital markets within the context of the global Covid-19 pandemic Nuno Miguel Delicado Teixeira, Pedro Nuno Coelho Palhão Bicho Pardal 2020 Oeconomia copernicana 10.24136/oc.2020.024 Team Researchers Other ResearchersNuno Miguel Delicado Teixeira Pedro Nuno Coelho Palhão Bicho Pardal