Shuifang, X. , Fengying, Z. , Yuhua, H. , Xiyun, L. , Jinfang, T. , YI, Q. and Fengying, X. 2020. Evaluation of the comparative influence of magnesium sulfate single and combination with ritodrine hydrochloride in the prevention of preterm delivery . Bioscience Journal. 36, 4 (May 2020), 1491–1497. DOI:https://doi.org/10.14393/BJ-v36n4a2020-49897.