Combined use of Chemical and Organic Fertilizers :   Proceedings of the seminar "Proper Use of Chemical Fertilizers. Combined with Organic Fertilizers in Crop Production". 
Zulkifli H. Shamsuddin, Ahmad Husni M. H. [y] Anuar A. R. 
 - malaysia 1992 
<br/><br/> Material bibliográfico para estudiantes universitarios, docentes e investigadores.