American Horticultural Society. The American daffodil year book. American Horticultural Society.
Chicago Style (17th ed.) CitationAmerican Horticultural Society. The American Daffodil Year Book. Washington, D.C.: American Horticultural Society.
MLA (9th ed.) CitationAmerican Horticultural Society. The American Daffodil Year Book. American Horticultural Society.
Warning: These citations may not always be 100% accurate.