[1] Cozzolino D, Moro′n A. Soil & Tillage Research, 2006, 85: 78.

[10] Galvo R K H, Araújo M C U, Fragoso W D. Chemometrics and Intelligent Laboratory Systems, 2008, 92(1): 83.

[11] Verboven S, Hubert M. Chemometrics and Intelligent Laboratory Systems , 2005, 75: 127.

[12] Galvo R K H, Araújo M C U, Jose G E, et al. Talanta, 2005, 67: 736.