Tài liệu tham khảo WikiPedia: Calendula http://www.botanical.com/botanical/mgmh/m/marigo16... http://www.ars-grin.gov/cgi-bin/npgs/html/genform.... http://compositae.landcareresearch.co.nz/Default.a... http://www.efloras.org/florataxon.aspx?flora_id=2&... http://www.theplantlist.org/browse/A/Compositae/Ca... http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree....
