Verbatim text: Heyn, C. C., O. Dagan, and B. Nachman. 1974. The annual Calendula species: Taxonomy and relationships. Israel J. Bot. 23: 169–201.
Author: Heyn, C.C., Dagan, O., Nachman, B.
Year: 1974
Title: The annual Calendula species: Taxonomy and relationships
Journal: Israel J. Bot
Volume: 23
Pages: 169–201