Stability of biomass-derived black carbon in soils - Liang, Biqing; Lehmann, Johannes; Solomon, Dawit; Sohi, Saran; Thies, Janice; Skjemstad, Jan O.; Luizão, Flavio Jesus; Engelhard, Mark H.; Neves, Eduardo Goes; Wirick, Sue (Geochimica et Cosmochimica Acta, 2008)