A concise proof for properties of three functions involving the exponential function. Zhang, Shi-Qin; Guo, Bai-Ni; Qi, Feng — 2009 Applied Mathematics E-Notes [electronic only]
Sharpening and generalizations of Shafer's inequality for the arc tangent function. Qi, Feng; Zhang, Shi-Qin; Guo, Bai-Ni — 2009 Journal of Inequalities and Applications [electronic only]