Prenner, Gerhard; Rudall, Paula J. (2007). "Comparative ontogeny of the cyathium in Euphorbia (Euphorbiaceae) and its allies: exploring the organ–flower–inflorescence boundary". American Journal of Botany. 94 (10): 1612–1629. doi:10.3732/ajb.94.10.1612. PMC 2999901. PMID 21151828. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2999901
Prenner, Gerhard; Rudall, Paula J. (2007). "Comparative ontogeny of the cyathium in Euphorbia (Euphorbiaceae) and its allies: exploring the organ–flower–inflorescence boundary". American Journal of Botany. 94 (10): 1612–1629. doi:10.3732/ajb.94.10.1612. PMC 2999901. PMID 21151828. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2999901