Li, R., J. Wang, X. Wang, and M. Wang. “ Pleural Effusion Adenosine Deaminase: A Candidate Biomarker to Discriminate Between Gram-Negative and Gram-Positive Bacterial Infections of the Pleural Space ”. Clinics, vol. 71, no. 5, May 2016, pp. 271-5, doi:10.6061/clinics/2016(05)05.