Goldblatt, P. (1976). «Cytotaxonomic studies in the tribe Quillajeae (Rosaceae)». Annals of the Missouri Botanical Garden. 63 (1): 200–206. doi:10.2307/2395226
Sterling, C. (1965). «Comparative morphology of the carpel in the Rosaceae. V. Pomoideae: Amelanchier, Aronia, Malacomeles, Malus, Peraphyllum, Pyrus, Sorbus». American Journal of Botany. 52 (4): 418–426. doi:10.2307/2440337
Campbell, C.S.; Evans, R.C.; Morgan, D.R.; Dickinson, T.A.; Arsenault, M.P. (2007). «Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history». Plant Systematics and Evolution. 266 (1–2): 119–145. doi:10.1007/s00606-007-0545-y
Potter, D.; Eriksson, T.; Evans, R.C.; Oh, S.H.; Smedmark, J.E.E.; Morgan, D.R.; Kerr, M.; Robertson, K.R.; Arsenault, M.P.; Dickinson, T.A.; Campbell, C.S. (2007). Phylogeny and classification of Rosaceae. Plant Systematics and Evolution. 266(1–2): 5–43. doi:10.1007/s00606-007-0539-9