H. Kai, M. Saito, K. Furuswa, Y. Oda, Y. Okano, K. Ta kahama and T. Miyata, “Protective Effect of Surface Ac tive Phospholipids against the Acid inducing Inhibitions of the Tracheal Mucociliary Transport,” The Japanese Journal of Pharmacology, Vol. 49, No. 3, 1989, pp. 375-380. doi:10.1254/jjp.49.375
 K. Rubin, O. Ramirez and M. King, “Mucus Rheology and Transport in Neonatal Respiratory Distress Syndrome and the Effect of Surfactant Therapy,” Chest, Vol. 101, No. 4, 1992, pp. 1080-1085. doi:10.1378/chest.101.4.1080
 M. Agarwal, M. King, B. K. Rubin and J. B. Shukla, “Mucus Transport in a Miniaturized Simulated Cough Machine: Effect of Constriction and Serous Layer Simu lant,” Biorheology, Vol. 26, No. 6, 1989, pp. 977-988.
 M. King, J. M. Zahm, D. Pierrot, S. Vaquez-Girod and E. Puchelle, “The Role of Mucus Gel Viscosity, Spinability and Adhesive Properties in Clearance by Simulated Cough,” Biorheology, Vol. 26, No. 4, 1989, pp. 737-745.
 M. Agarwal, M. King and J. B. Shukla, “Mucous Gel Transport in a Simulated Cough Machine: Effects of Lon gitudinal Grooves Representing Spacing between Arrays of Cilia,” Biorheology, Vol. 31, No. 1, 1994, pp. 11-19.
 D. K. Satpathi, B. V. Rathish Kumar and P. Chandra, “Unsteady Sate Laminar Flow of Viscoelastic Gel and Air in a Channel: Application to Mucus Transport in a Cough Machine Simulated Trachea,” Mathematical and Com puter Modeling, Vol. 38, No. 1-2, 2003, pp. 63-75. doi:10.1016/S0895-7177(03)90006-9
 P. Camner, B. Mossberg, K. Philipson and G. Strandberg, “Elimination of Test Particles from Human Tracheo bronchial Tract by Voluntary Coughing,” Scandinavian Journal of Respiratory Diseases, Vol. 60, No. 2, 1979, pp. 56 62.
 A. Saxena, A. P. Tyagi and R. Saxena, “Mathematical Modeling of Mucus Transport in the Lung Due to Pro longed Cough: Effect of Resistance to Flow by Serous Fluid in Cilia Bed,” International Journal of Mathemati cal Science, Vol. 10, No. 1-2, 2011, pp. 9-20.
 H. Rensch and H. Von Seefeld, “Surfactant Mucus Inter action in Pulmonary Surfactant,” In: B. Robertson, L. M. G. Von Golde and J. J. Batunberg, Eds., Pulmonary Sur factant: From Molecular Biology to Clinical Practice, Elsevier Science Publishers, Amsterdam, 1984, pp. 203 214.
 R. Banerjee and R. R. Puniyani, “Analysis of Dynamic Surface Properties of Therapeutic Surfactants and Lung Phospholipids,” Journal of Biomaterials Applications, Vol. 14, No. 3, 2000, pp. 243-272. doi:10.1106/9D4B-L6PP-7CTF-BY8G