5. REFERENCES

For grand overview of underlying methods see:

Ghil M., R. M. Allen, M. D. Dettinger, K. Ide, D. Kondrashov, M. E. Mann,
A. Robertson, A. Saunders, Y. Tian, F. Varadi, and P. Yiou, 2000: Advanced spectral methods for climatic time series, Rev. Geophys.,40(1), pp. 3.1-3.41, 10.1029/2000GR000092, read it here.