^Wang, W.; Sun, Y. (2008). "Ultrasonic Extraction of Ferulic Acid from Ligusticum chuanxiong". Journal of the Chinese Institute of Chemical Engineers. 39 (6): 653–656. doi:10.1016/j.jcice.2008.05.012.
^US patent 5336513, Riemer, J. A., "Bitterness Inhibitors", issued 1994-08-09, assigned to Kraft General Foods (expired in 2006 due to non-payment of fees)