1. Soil and plant analysis;Ankerman,1979
2. Atomic absorption and flame emission spectroscopy;Baker,1982
3. Humic acid products getting good results in Indian River groves;Bateman;Citrus Veg. Mag.,1988
4. Humic acid products getting good results in Indian River groves;Bateman;Citrus Veg. Mag.,1988
5. Humic acid products getting good results in Indian River groves;Bateman;Citrus Veg. Mag.,1988