Review Marigold (Calendula officinalis L.): an evidence-based systematic review by the Natural Standard Research Collaboration.
Basch E, Bent S, Foppa I, Haskmi S, Kroll D, Mele M, Szapary P, Ulbricht C, Vora M, Yong S, et al. J Herb Pharmacother. 2006; 6(3-4):135-59.