Crataegus crus-galli in Flora of North America @ efloras.org. www.efloras.org [online]. [cit. 2022-04-12]. Dostupné online.
iucnredlist.org
apiv3.iucnredlist.org
The IUCN Red List of Threatened Species 2022.2. 9. prosince 2022. Dostupné online. [cit. 2023-01-04].
kew.org
powo.science.kew.org
Crataegus crus-galli L. | Plants of the World Online | Kew Science. Plants of the World Online [online]. [cit. 2022-04-12]. Dostupné online. (anglicky)