@article{article47e7c04e,
title   = {Studies of the compositions of humic acids from Amazonian Dark Earth soils},
author = {Novotny, Etelvino Henrique and Azevêdo, Eduardo Ribeiro de and Bonagamba, Tito José and Cunha, Tony J. F. and Madari, Beata Emoke and Benites, Vinicius de M. and Hayes, Michael H. B.},
year = {2007},
journal   = {Environmental Science and Technology}
}