↑ Phipps, JB (2015), " Crataegus marshallii Eggleston in NL Britton and JA Shafer, N. Amer. Trees. 473. 1908" , in L. Brouillet; K. Gandhi; CL Howard; H. Jeude; RW Kiger; JB Phipps; AC Pryor; HH Schmidt; JL Strother; JL Zarucchi (eds.), Magnoliophyta: Picramniaceae to Rosaceae , Flora of North America North of Mexico, vol. 9, New York, Oxford: Oxford University Press