L. Hasanah, K. Khairurrijal, M. Abdullah, T. Winata, and S. Sukirno, “An Improved Analytic Method Based on Airy Functions Approach to Calculate Electron Direct Transmittance in Anisotropic Heterostructure with Bias Voltage”, ijp, vol. 17, no. 3, pp. 77-81, Nov. 2016.