山羊百科，林文智老師的植物、山岳、攝影紀錄

Part I

• 《中国植物志》 第36卷 (1974) >> 186页 PDF >> 山楂属 Crataegus；http://www.iplant.cn/info/CRATAEGUS?t=z

• CRATAEGUS；Flora of North America；http://floranorthamerica.org/Crataegus

• Illustriertes Handbuch der Laubholzkunde Illustriertes Handbuch der Laubholzkunde; 1904 https://archive.org/stream/mobot31753002689237#page/768/mode/1up

• Persoon, Syn. Pl. 2: 36 1806；https://www.biodiversitylibrary.org/item/11127#page/39/mode/1up

Synopsis plantarum,seu Enchiridium botanicum, complectens enumerationem systematicam specierum hucusque cognitarum

Part II

• Pojark., Fl. URSS 9: 317 (1939)；https://www.biodiversitylibrary.org/item/95694#page/345/mode/1up

• Sarg., Rhodora 5: 150 (1903).；https://www.biodiversitylibrary.org/page/562122#page/158/mode/1up
• Crataegus severa Sarg., Trees & Shrubs [Sargent] 2: 59, pl. 127 (1908).；https://www.biodiversitylibrary.org/page/39881059#page/97/mode/1up

Part III

1. Ibrahimov, A. M., Matsyura, A. V., & Jankowski, K. (2020). Taxonomy of the wild species of genus Crataegus (Rosaceae): An updated review for the flora of Nakhchivan Autonomous Republic (Azerbaijan). Biosystems Diversity 28(4): 445–454