Dr. PRAKASH M, Dr. HARI P M, & Dr. PAVITHRA SAIKUMAR. (2017). Bronchial challenge in perennial allergic rhinitis patients without asthma – A clinico spirometric correlation. International Journal of Pharma and Bio Sciences, 8(2), 696–700. https://doi.org/10.22376/ijpbs.2017.8.2.b696-700