Stock, J. H., & Watson, M. W. (2020). Introduction to econometrics (Fourth edition). Pearson Education Limited. https://bibliu.com/users/saml/samlUCL?RelayState=eyJjdXN0b21fbGF1bmNoX3VybCI6IiMvdmlldy9ib29rcy85NzgxMjkyMjY0NTIzL3BkZjJodG1sZXgvaW5kZXguaHRtbCJ9