Docu update.

doc/tex/bib.tex

@@ -111,7 +111,7 @@
 
 
 \bibitem[Preisendorfer]{Preisendorfer} \ \\
-  Rudolph W. Preisendorfer: Principal Component Analysis, Elsevier (1988)
+  Rudolph W. Preisendorfer: Principal Component Analysis in Meteorology and Oceanography, Elsevier (1988)
 
 
 \bibitem[PROJ]{PROJ} \ \\

doc/tex/ref_intro_eofs.tex

 This section contains modules to compute Empirical Orthogonal Functions and 
 - once they are computed - their principal coefficients. \\
 An introduction to the theory of principal component analysis as applied here can be found in:\\ 
-\hspace*{1cm} Principal Component Analysis \cite{Preisendorfer} \\
+\hspace*{1cm} Principal Component Analysis in Meteorology and Oceanography \cite{Preisendorfer} \\
 Details about calculation in the time- and spatial spaces are found in:\\
 \hspace*{1cm} Statistical Analysis in Climate Research \cite{vonStorch}