海量图书期刊资源，随时随地畅享阅读乐趣
A study of nodulation and nitrogen fixation of alder on the purplish soils in ChinaLiu Guofan; Deng Tingxiu · 1987
Mathematical model of the relationship between nitrogen-fixation by black locust and soil conditionsGuofan Liu; Tingxiu Deng · 1991