[1] Bendat, Julius S., Piersol, Allan G.: 
Measurement and Analysis of Random Data. John Wiley & Sons, Inc., New York-London-Sydney 1966. 
MR 0356404 
[2] Blackman R. B., Tukey J. W.: 
The Measurement of Power Spectra. Dover Publications, Inc., 180 Varick Street, New York 14, N. Y. 
Zbl 0084.21703 
[3] Davenport, Wilbur B., Root, William L.: 
An Introduction to the Theory of Random Signals and Noise. McGraw-Hill Book Company, Inc., New York-Toronto-London 1958. 
MR 0092275 
[4] Kreil W., Schweizer G.: Auswertung stochastischer Messwerte. Dornier Report No. F-5614 08, Oct. 1966; will be published in „Beihefte zur NTZ".