Canadensys: University of Alberta Vascular Plant Herbarium (ALTA-VP)
Canadensys, operated from the Université de Montréal Biodiversity Centre
"66684 - Sonchus asper (L.) Hill, University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/12-169015. Accessed 21 May. 2025.