Zia Ziabari, S.M. et al. 2019. Blood Urea Nitrogen to Creatinine ratio in Differentiation of Upper and Lower Gastrointestinal Bleedings; a Diagnostic Accuracy Study. Archives of Academic Emergency Medicine. 7, 1 (Jun. 2019), e30. DOI:https://doi.org/10.22037/aaem.v7i1.400.