Doan, T., Le, V., To, H. and Ngo, T. 2019. Investigation a clean up procedure for chlorophenols in soil by ultrasonic and solid phase extraction. Science & Technology Development Journal: Natural Sciences. 2, 2 (May 2019), 118-124. DOI:https://doi.org/https://doi.org/10.32508/stdjns.v2i2.744.