Sunyal, Dipok Kumar, et al. “Study of Forced Expiratory Volume in First Second (FEV1) and Ratio of Forced Expiratory Volume in First Second and Forced Vital Capacity in Percentage (FEV1 FVC%) in Pregnant Women”. Journal of Enam Medical College, vol. 2, no. 1, Sept. 2012, pp. 29-32, doi:10.3329/jemc.v2i1.11926.