1. Drennan, Dana L., 1980. Flower quality as a component of a breeding project with Gerbera jamesonii. M.S. Thesis, University of California, Davis.
2. Drennan, Dana L., Ronald W. Hodgson & James Harding, 1980. Methods for selecting flower quality based on consumer evaluation. Euphytica 29: 641–651.
3. Falconer, D. S., 1960. Introduction to quantitative genetics. Oliver and Boyd, Edinburgh.
4. Harding, James, Dana L. Drennan & Thomas G. Byrne, Components of genetic variability for flower yield through 7 generations of selection in the Davis population of Gerbera. In preparation.
5. Harding, James, Thomas G. Byrne & Robert L. Nelson, 1981. Estimation of heritability and response to selection for cut-flower yield in Gerbera. Euphytica 30: 313–322.