1. Handbook of Mathematical Functions;Abramowitz;National Bureau of Standards Applied Mathematics Series No. 55,1964
2. Asymptotic Expansions;Erdélyi,1956
3. Supplément au formulaire pour le calcul symbolique;Humpert,1950
4. Spectral properties of Schrödinger operators and time-decay of the wave functions;Jensen;Duke Math. J.,1979