TY  - JOUR 
T1  - Chemical and Spectroscopical Characterization of Humic Acids from two South Brazilian Coals of Different Ranks
JO  - Journal of the Brazilian Chemical Society
A1  - Dick, Deborah P.
A1  - Mangrich, Antonio S.
A1  - Menezes, Sonia M. C.
A1  - Pereira, Betania F.
SN  - 0103-5053
UL  - 10.1590/S0103-50532002000200008
VL  - 13 
Y1  - 2002
PB  - Brasil 
ER  -