1. Apple tree growth, net photosynthesis, dark respiration, and specific leaf weight as affected by continuous and intermittent shade;Barden;J. Am. Soc. Hortic. Sci.,1977
2. Effect of K level on frost hardiness of stems of Forsythia × intermedia Zab. ‘Lynwood’;Beattie;J. Am. Soc. Hortic. Sci.,1973
3. A method for determining hardiness in plants;Dexter;Science,1930
4. Geographic variation in eastern redbud;Donselman,1976
5. Effects of Shade and Fertility on the Growth of Landscape Shrubs;Euchner,1977