Dan-Dan, H., C. Jian-Qiu, L. Xin-Qiao, Z. Yan, and J. Yi-Bing. “Concentration of Astragalus Polysaccharide by Polysulfone-Activated Carbon Modified With Nitric Acid Blend Ultrafiltration Membranes”. Journal of Membrane and Separation Technology, vol. 2, no. 1, Feb. 2013, pp. 27-35, doi:10.6000/1929-6037.2013.02.01.3.