1. Quasi-Biennial and Long-Term Fluctuations In Total Ozone
2. Evolution of the Psilophyte Paleoflora
3. On the Origin and Rise of Oxygen Concentration in the Earth's Atmosphere
4. Biggs, R. H., W. B. Sisson, and M. M. Cald-well. 1975. Response of higher terrestrialplants to elevated UV-B irradiance. Pages4-34 to 4-50 in D. S. Nachtwey, M. M.Caldwell, and R. H. Biggs, eds. Impacts ofClimatic Change on the Biosphere, Part 1:Ultraviolet Radiation Effects (CIAPMonog. 5). U.S. Department of Transporta-tion, Springfield, VA.BiggsResponse of higher terrestrial plants to elevated UV-B irradiance4Impacts of Climatic Change on the Biosphere, Part 1: Ultraviolet Radiation Effects (CIAP Monog. 5)1975