https://scholar.google.com/scholar_lookup?title=Hydroxylated+Phytosiderophore+Species+Possess+an+Enhanced+Chelate+Stability+and+Affinity+for+Iron(III)&author=von+Wirén,+N.&author=Khodr,+H.&author=Hider,+R.C.&publication_year=2000&journal=Plant+Physiol.&volume=124&pages=1149–1158&doi=10.1104/pp.124.3.1149&pmid=11080292