Pendall, E., Leavitt, S., Brooks, T., Kimball, B., Pinter Jr., P., Wall, G., LaMorte, R., Wechsung, G., Wechsung, F., Adamsen, F., Matthias, A., Thompson, T. (2001): Elevated CO2 stimulates soil respiration in a FACE wheat field. - Basic and Applied Ecology, 2, 3, 193-201.