1. D.S. Robinson (Ed.), Bioquı́mica y Valor Nutritivo de los Alimentos, Editorial ACRIBIA, S.A., Zaragoza, Spain, 1991.
2. G. Perkins (Ed.) Analysis of Fats, Oils and Lipoproteins, American Oil Chemist's Society, Champaign, IL, USA, 1991.
3. Extraction of oil from pressed palm oil (Elaes guineensis) fibers using supercritical CO2;França;Ciência e Tecnologia de Alimentos,1997
4. K. Zosel, Process for recovering caffeine, US Patent No. 3 806 619, 1974.
5. D.R.J. Laws, N.A. Bath, C.S. Ennis, A.G. Wheldon, Hop extraction with carbon dioxide, US Patent No. 4 218 491, 1980.