Pleural adenosine deaminase in the diagnostic workup of tuberculous pleural effusion.

1. Bonilha A, Onofre F, Vieira M, Prado M, Martinez J. Effects of singing classes on pulmonary function and quality of life of COPD patients. Int J COPD. 2009;4:1--8. 2. Lord V, Cave P, Hume V, Flude E, Evans A, Kelly J, et al. Singing teaching as a therapy for chronic respiratory disease -a randomised controlled trial and qualitative evaluation. BMC Pulm Med. 2010;10:41. 3. Global strategy for the diagnosis, management and prevention of COPD, global initiative for chronic obstructive lung disease (GOLD); 2013. Available from: http://www. goldcopd.org/ 4. Lord V, Hume V, Kelly J, Cave P, Silver J, Waldman M, et al. Singing classes for chronic obstructive pulmonary disease: a randomized controlled trial. BMC Pulm Med. 2012;12:69. 5. Hoit JD, Jenks CL, Watson PJ, Cleveland TF. Respiratory function during speaking and singing in professional country singers. J Voice. 1996;10:39--49. 6. Grape C, Sandgren M, Hansson LO, Ericson M, Theorell T. Does singing promote well-being? An empirical study of professional and amateur singers during a singing lesson. Integr Physiol Behav Sci. 2003;38:65--74.