Readers should cite both the Bio-protocol preprint and the original research article where this protocol was used:

Yu, H, Luo, W and Li, Y(2020). Quantification of plasma bile acids and bilirubin. Bio-protocol Preprint. bio-protocol.org/prep296.
Yu, H., Zhao, T., Liu, S., Wu, Q., Johnson, O., Wu, Z., Zhuang, Z., Shi, Y., Peng, L., He, R., Yang, Y., Sun, J., Wang, X., Xu, H., Zeng, Z., Zou, P., Lei, X., Luo, W. and Li, Y.(2019). MRGPRX4 is a bile acid receptor for human cholestatic itch. eLIFE. DOI: 10.7554/eLife.48431