Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi R, et al. Interpretative strategies for lung function tests. Eur Respir J 2005; 26:948–968.
Modrykamien AM, Gudavalli R, McCarthy K, Liu X, Stoller JK. Detection of upper airway obstruction with spirometry results and the flow-volume loop: a comparison of quantitative and visual inspection criteria. Respir Care 2009; 54:474–479.
Golish JA, Ahmad M, Yarnal JR. Chronic upper airway obstruction. Methods of detection and recognition. Cleve Clin Q 1980; 47:9–15.
France JE, Thomas MJC. Clinical use of the Empey index in the emergency department. Emerg Med J 2004; 21:642–643.
Miller RD, Hyatt RE. Evaluation of obstructing lesions of the trachea and larynx by flow-volume loops. Am Rev Respir Dis 1973; 108:475–481.
Guntupalli KK, Bandi V, Sirgi C, Pope C, Rios A, Eschenbacher W. Usefulness of flow volume loops in emergency center and ICU settings. Chest 1997; 111:481–488.
Karkhanis VS, Desai U, Joshi JM. Flow volume loop as a diagnostic marker. Lung India 2013; 30:166–168.
Gibson GJ. Central airway obstruction and bronchial carcinoma. In: Gibson GJ, editor. Clinical tests of respiratory function. 3rd ed. New Delhi: Jaypee Brothers; 2009. 221–234.
Eckel HE, Sittel C. Bilateral recurrent laryngeal nerve paralysis. HNO 2001; 49:166–179.
Prepageran N, Raman R. Delayed complication of radiotherapy: laryngeal fibrosis and bilateral vocal cord immobility. Med J Malaysia 2005; 60:377–378.