M. M. Billington

Site-to-site variations in nitrogenase activity in a subarctic black spruce forest

V. Alexander, M. M. Billington, 1983 .

Nitrogen Fixation in Arctic and Alpine Tundra

D. Schell, V. Alexander, M. M. Billington, 1978 .

Nitrogen Fixation in the Alaskan Taiga

V. Alexander, M. M. Billington, 1986 .