1. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables,1972
2. Some classes of completely monotonic functions;Alzer;Ann. Acad. Sci. Fenn.,2002
3. New closed-form approximations to the logarithmic constant e;Brothers;Math. Intelligencer,1998
4. Sur les fonctions quasi-analytiques;Carleman,1922
5. On an infinite series for (1+1/x)x and its application;Chen;Int. J. Math. Math. Sci.,2002