@ARTICLE {SANGINGA:1991b, title = {Variation in nodulation and N2 fixation by the Gliricidia sepium/Rhizobium spp. symbiosis in a calcareous soil}, author = {Sanginga, N. and Manrique, K. and Hardarson, G. }, journal = {Biology and Fertility of Soils}, year = {1991}, volume = {11}, number = {4}, pages = {273--278}, }