Estimated impact of biogenic hydrocarbon emissions on photochemical oxidant formation en São Paulo during two periods of the winters of 1999-2000 - Martins, Leila Droprinchinski; Vasconcellos, Pérola de Castro; Carvalho, Lilian Rothschild Franco de; Andrade, Maria de Fátima (Revista Brasileira de Meteorologia, 2006)