Supplementary material to "Investigation of secondary formation of formic acid: urban environment vs. oil and gas producing region"
B. Yuan,P. R. Veres,C. Warneke,J. M. Roberts,J. B. Gilman,A. Koss,P. M. Edwards,M. Graus,W. C. Kuster,S.-M. Li,R. J. Wild,S. S. Brown,W. P. Dubé,B. M. Lerner,E. J. Williams,J. E. Johnson,P. K. Quinn,T. S. Bates,B. Lefer,P. L. Hayes,J. L. Jimenez,R. J. Weber,R. Zamora,B. Ervens,D. B. Millet,B. Rappenglück,J. A. de Gouw