Lane C, Knight D, Burgess S et al. (September 2004). "Epithelial inducible nitric oxide synthase activity is the major determinant of nitric oxide concentration in exhaled breath". Thorax 59 (9): 757–60. doi:10.1136/thx.2003.014894. PMC 1747143. PMID15333851
Brindicci C, Ito K, Barnes PJ, Kharitonov SA (August 2007). "Effect of an inducible nitric oxide synthase inhibitor on differential flow-exhaled nitric oxide in asthmatic patients and healthy volunteers". Chest 132 (2): 581–8. doi:10.1378/chest.06-3046. PMID17550932