Ramamurthy, P. C., K. K. Khadija, K. Ranjith, and S. R. Mishra. “Fabrication of Hollow Microspheres Using Single Step Electrospraying Process”. Journal of Research Updates in Polymer Science, vol. 3, no. 2, June 2014, pp. 108-13, doi:10.6000/1929-5995.2014.03.02.5.