ISBN 9780891181040 books & textbook
Humic Substances in Soil and Crop Sciences: Selected Readings : Proceedings of a Symposium Cosponsored by the International Humic Substances Society
Maccarthy, P. Clapp, C. E. Malcolm, R. L. Bloom, P. R.
Amer Society of Agronomy /1990T Hardcover / 281 Pages
isbn-10: 0891181040 / isbn-13: 9780891181040
