Querol, X., Alastuey, A., Rodriguez, S., Viana, M.M., Artinano, B., Salvador, P., Mantilla, E., do Santos, S.G., Patier, R.F., de La Rosa, J., de la Campa, A.S., Menendez, M., Gil, J.J. 2004. Levels of particulate matter in rural, urban and industrial sites in Spain. SCIENCE OF THE TOTAL ENVIRONMENT, 334:359-376.