"Genus: Plantago L."Germplasm Resources Information Network. United States Department of Agriculture. 2006-04-20. Archived from the original on 2009-01-15. Retrieved 2011-03-04.
"Genus: Plantago L."Germplasm Resources Information Network. United States Department of Agriculture. 2006-04-20. Archived from the original on 2009-01-15. Retrieved 2011-03-04.