1. Daylight a factor in flowering;Allard;U. S. Dept. Agric. Yearbook.,1927
2. Length of day in relation to the natural and artificial distribution of plants;Allard;Ecology,1932
3. Some effects of the photoperiod on development of Impatiens balsarnea;Austin;Pl. Physiol.,1935
4. Effect of the relative length of day and night and other factors of the environment on growth and reproduction in plants;Garner;Jour. Agric. Res.,1920
5. Further studies in photoperiodism, the response of the plant to relative length of day and night;Garner;Jour. Agric. Res.,1923