- Zhen-Hang Yang, Jing-Feng Tian, “Monotonicity, convexity, and complete monotonicity of two functions related to the gamma function”, RACSAM, 113, № 4, 2019, 3603

- Feng Qi, Ravi P. Agarwal, “On complete monotonicity for several classes of functions related to ratios of gamma functions”, J Inequal Appl, 2019, № 1, 2019, 36

- Feng Qi, Cristinel Mortici, “Some inequalities for the trigamma function in terms of the digamma function”, Applied Mathematics and Computation, 271, 2015, 502

- Xu You, Di-Rong Chen, “Improved Approximation Formulas and Inequalities for the Wallis Ratio”, Bull. Iran. Math. Soc., 45, № 3, 2019, 783

- Zhen-Hang Yang, “Some properties of the divided difference of psi and polygamma functions”, Journal of Mathematical Analysis and Applications, 455, № 1, 2017, 761

- Feng Qi, Wen-Hui Li, Shu-Bin Yu, Xin-Yu Du, Bai-Ni Guo, “A ratio of finitely many gamma functions and its properties with applications”, RACSAM, 115, № 2, 2021, 39

- Feng Qi, Wen-Hui Li, “A LOGARITHMICALLY COMPLETELY MONOTONIC FUNCTION INVOLVING THE RATIO OF GAMMA FUNCTIONS”, jaac, 5, № 4, 2015, 626

- Zhen-Hang Yang, Jing-Feng Tian, “Windschitl type approximation formulas for the gamma function”, J Inequal Appl, 2018, № 1, 2018, 272

- Chao-Ping Chen, “A more accurate approximation for the gamma function”, Journal of Number Theory, 164, 2016, 417

- Feng Qi, Cristinel Mortici, “Some best approximation formulas and inequalities for the Wallis ratio”, Applied Mathematics and Computation, 253, 2015, 363
