1. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables;Abramowitz,1972
2. J. O’Connor, E.F. Robertson, James Stirling, MacTutor History of Mathematics Archive.
3. J. Stirling, Methodus differentialis, sive tractatus de summation et interpolation serierum infinitarium, London, 1730. English translation by J. Holliday, The Differential Method: A Treatise of the Summation and Interpolation of Infinite Series.
4. A rapidly convergent series for logN!;Burnside;Messenger Math.,1917
5. Inequalities for the gamma function;Batir;Arch. Math.,2008