1. Bender, C.M., Orszag, S.A.: 1978, Advanced Mathematical Methods for Scientists and Engineers, McGraw-Hill, New York.
2. Birch, A.C., Braun, D.C., Hanasoge, S.M., Cameron, R.: 2008, Solar Phys. doi: 10/1007/s11207-008-9282-9 .
3. Bogdan, T.J., Cally, P.S.: 1997, Proc. Roy. Soc. Lond. A 453, 943.
4. Braun, D.C., Birch, A.C.: 2006, Astrophys. J. Lett. 647, L187.
5. Braun, D.C., Birch, A.C.: 2008, Solar Phys. 251, 267.