Khatun, A., J. Begum, F. Naznin, R. Parvin, M. Rahman, S. Sayem, and E. Chowdhury. “Cytological Evaluation of Necropsy Guided Impression Smears of Chronic Respiratory Disease of Chickens”. SAARC Journal of Agriculture, vol. 10, no. 2, Mar. 2014, pp. 95-105, doi:10.3329/sja.v10i2.18331.