Wilson, R.; van Schie, B.J.; Howes, D. (1998). "Overview of the Preparation, Use and Biological Studies on Polyglycerol Polyricinoleate (PGPR)". Food and Chemical Toxicology. 36 (9–10): 711–8. doi:10.1016/S0278-6915(98)00057-X. PMID9737417.
Wilson, R.; van Schie, B.J.; Howes, D. (1998). "Overview of the Preparation, Use and Biological Studies on Polyglycerol Polyricinoleate (PGPR)". Food and Chemical Toxicology. 36 (9–10): 711–8. doi:10.1016/S0278-6915(98)00057-X. PMID9737417.