1. Wershaw , R.L. 1985. “Humic Substances in Soil, Sediment and Water”. Edited by:
Aiken , G.R. 561–82. N.Y.: John Wiley and Sons.
2. CARBON-13 NUCLEAR MAGNETIC RESONANCE FOR A HUMIC AND A FULVIC ACID
3. Steelink , C.
Thorn , K. and
Mikita , M.A. 1983. “Aquatic and Terrestrial Humic Materials”. Edited by:
Christman , R.L. and
Gjessing , E.T. 87–104. Ann Arbor, MI: Ann Arbor Science.
4. Sarkanen , K.V. and
Ludwig , C.H. 1971. “Lignins: Occurrence, Formation, Structure and Reactions”. 788N.Y.: Wiley‐Interscience.
5. Stevenson , F.J. 1982. “Humus Chemistry: Genesis, Composition, Reactions”. 247N.Y.: Wiley‐Interscience.