1. Piironen, Vieno; Toivo, Jari; Puupponen-Pimi, Riitta; Lampi, Anna-Maija: Plant sterols in vegetables, fruits and berries J Sci Food Agric. 2003;83:330.
  2. Piironen, V.; Lindsay, D. G.; Miettinen, T. A.; Toivo, J.; Lampi, A. M.: Plant sterols: biosynthesis, biological function and their importance to human nutrition J Sci Food Agric. 2000;80:939.
  3. Alan Crozier, Mike N. Clifford, Hiroshi Ashihara (2006). Plant Secondary Metabolites: Occurrence, Structure and Role in the Human Diet. Blackwell publiching. [ISBN:978-1-405-12509-3 ]