no symbols in export to rtf-file

Hello, is there anybody who can help us finding the solution for the following problem?
With the help of Oracle we enter information on articles in a database on a website. The titles of these articles often contain symbols like mu, nu, sigma etc., and sometimes even equations. Until recently it was not possible to enter these characters in the database, they didn't show when opening the data lateron. Now that is fixed, but another - even bigger - problem remains: once exported to a rtf or a print, the symbols disappear, are preceeded by another strange character (not entered!) or become little blocks. How can we solve this? Can it be solved at all anyway? Or will the only possibility be entering [sigma] or [Sigma], and replace those lateron in the text file?
For your information: I am a secretary here, not a programmer... but nobody here (at the faculty of (exact) sciences) seems to know...

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Gis le Cass e
Vrije Universiteit Amsterdam