^Tao YM, Li QL, Zhang CF, Xu XJ, Chen J, Ju YW, Chi ZQ, Long YQ, Liu JG (April 2008). "LPK-26, a novel kappa-opioid receptor agonist with potent antinociceptive effects and low dependence potential". European Journal of Pharmacology. 584 (2–3): 306–11. doi:10.1016/j.ejphar.2008.02.028. PMID18353307.