New asymptotic expansion for the Gamma function

E.T. Copson, Asymptotic Expansions, Cambridge University Press, 1965.

E. Whittaker and G. Watson, A Course of Modern Analysis, Cambridge University Press, 1963, 251–253.

M. Abramowitz and I. A. Stegun (eds.), Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, National Bureau of Standards, Applied Mathematical Series, 55, 9th printing, Dover, New York, 1972, 804.

P. Luschny, An overview and comparison of different approximations of the factorial function, http://www.luschny.de/math/factorial/approx/SimpleCases.html , 2007.

S. Ragahavan and S. S. Rangachari (eds.), S. Ramanujan: The lost notebook and other unpublished papers, Narosa Publ. House, Springer, New Delhi, Berlin, 1988.