Canadensys: University of Alberta Vascular Plant Herbarium (ALTA-VP)
Canadensys, operated from the Université de Montréal Biodiversity Centre
"9432 - Arabis holboellii Hornem. var. retrofracta (Graham) Rydb., University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/12-117307. Accessed 17 Mar. 2025.