References
- Nagle R. K. Saff E. B. Snider A. D. 2000 Fundamentals of Differential Equations 5th ed. Addison Wesley
- Adomian , G. 1991 . Comput. Math. Appl. , 21 ( 5 ) : 101 – 127 .
- Abramowitz M. Stegun I. A. 1990 Handbook of Mathematical Functions New York Dover