Goodman, B A <br/><br/>
Electron paramagnetic resonance evidence that copper is complexed in humic acid by the nitrogen of porphyrin groups.  [electronic resource] 

 -  Nature: New biology  Aug 1973 
 - 158-9 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0090-0028 
<br/><br/><label>Standard No.: </label>10.1038/newbio244158a0  doi 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Copper--analysis<br/>Humic Substances--analysis<br/>Magnetic Resonance Spectroscopy<br/>Nitrogen--analysis<br/>Porphyrins--analysis<br/>Soil--analysis