Huang SS, Kaysen GA, Levin NW, Kliger AS, Beck GJ, Rocco MV, Filler G, Lindsay RM. The effect of increased frequency of hemodialysis on serum cystatin C and ß2-microglobulin concentrations: A secondary analysis of the frequent hemodialysis network (FHN) trial. Hemodial Int. 2019 07; 23(3):297-305.