Definition of willow warbler:
"{{quote-journal|pagetitle=followable|year=2009|date=January 27|author=Hartry Field|title=Epistemology without metaphysics|work=Philosophical Studies|doi=10.1007/s11098-009-9338-1|volume=143|issue=2|pages=249-290"
Definition of willow warbler:
"{{quote-journal|pagetitle=followable|year=2009|date=January 27|author=Hartry Field|title=Epistemology without metaphysics|work=Philosophical Studies|doi=10.1007/s11098-009-9338-1|volume=143|issue=2|pages=249-290"