Cause of colour break in daffodils, Hunter, D. et al; Report No. 1800; 2007, ADS-sponsored research

Bulb scale mites and narcissus, Central Science Lab, Sand Hutton, York, England, 2003

“Report from UCI,” Harold Koopowitz, The Daffodil Journal, March 2002

“Pickling your Paperwhites,” Cornell University.  This article is about controlling the length of the stems in pots of paperwhites.

  Evolution & maintenance of stigma-height dimorphism in Narcissus. Paper II, funded by an operating grant from the Natural Sciences and Engineering Research Council of Canada (NSERC) to S.C.H.B. and a grant from CNRS to J.D.T. A.M.B. was supported by graduate scholarships from NSERC and the Ontario government, May 1999