^Phipps, J.B. (2015). "Crataegus visenda Beadle". In L. Brouillet; K. Gandhi; C.L. Howard; H. Jeude; R.W. Kiger; J.B. Phipps; A.C. Pryor; H.H. Schmidt; J.L. Strother; J.L. Zarucchi (eds.). Magnoliophyta: Picramniaceae to Rosaceae. Flora of North America: North of Mexico. Vol. 9. Oxford University Press. p. 613.
^ abPhipps, J.B.; Dvorsky, K.A. (2007). "Review of Crataegus series Apricae, ser. nov., and C. flava (Rosaceae)". Journal of the Botanical Research Institute of Texas. 1 (1): 171–202. JSTOR41971408.
External links
Zvezdana Ukropina-Crawford, "Crataegus tristis Beadle", Discoveries of the New Plants Species in Northeast Georgia, Southeastern United States in the Late 19th and Early 20th Centuries, retrieved 3 May 2015