Mohd, T. A. T., et al. “Aqueous Foams Stabilized With Silica Nanoparticle and Alpha Olefin Sulfonates Surfactant”. Journal of Mechanical Engineering and Sciences, vol. 12, no. 3, Sept. 2018, pp. 3759-70, doi:10.15282/jmes.12.3.2018.1.0332.