Copyright for all material on the site
is of Christian Lehmann, Universität Erfurt. Anyone may use, but not multiply, this material under condition of mention of the name of the copyright owner and this site (example of quotation).
Apart from theory and methodology, these pages also contain many facts and data, some with, some without indication of the source. I will be grateful for any corrections, and I hereby express my sincere thanks to those people – too many to be enumerated here – who have helped me improve this site.
Searching these pages
Google has not crawled this site exhaustively. One can, however, search it by using the ‘Suchen’ button on the home page.
Technical notes
Browser (version)
Different browsers display incorrectly different elements of these pages. For instance, the IE upto version 6 does not display the title of the header frame. I have made no attempt to remedy such shortcomings.
Screen display
Screen layout is designed for full-screen display at a resolution of 1024 x 768 pixels. You may gain vertical space by pressing the F11 key (and you will see your navigation bars again by pressing it again).
The files are hypertext files, not traditional text files. This means they have been designed for use on the screen, not for print. This concerns foremost a multiplicity of links to other files and databases. It also concerns the layout: many graphic presentations do not fit on a sheet of paper. Some information is coded by colors and shading. It gets lost if files are printed with a monochromous printer.
Moreover, different browsers make different mistakes in printing the files.
Special characters
The texts are replete with special characters. If you want to see them, a unicode font must be installed. ‘Arial Unicode MS’ is generally installed on Windows computers.
For technical reasons, no special characters are used in the popup definitions. The emergency solution used here for their replacement is unsatisfactory and not recommended for imitation.