B. M. Saraiva-Romanholo, F. S. Machado, F. M. Almeida, M. do P. T. Nunes, M. A. Martins, and J. E. Vieira, “ Non-asthmatic patients show increased exhaled nitric oxide concentrations ”, Clinics, vol. 64, no. 1, pp. 5–10, Jan. 2009, doi: 10.1590/S1807-59322009000100002.