2R W Willey. Intercropping Its impor- tance and research needs. Part II.Agronomy and research approaches[J].Field Crops Abstract,1979,32(2):73-85.
3WILLEY R W. Intereropping-Its importance and research needs. Part II. Agronomy and research approaches [ J]. Field Crops Abstract, 1979, 32 (2) : 73-85.