When importing references into software like EndNote or RefWorks you might find special characters and diacritical marks are stripped out.
You can edit the reference in the software and re-insert the appropriate character in several ways:
1) Copy and past the character in.
2) If you using a Windows computer with a number pad you can hold down the ALT key and type in a numerical code for the character you want e.g. ALT 130 will insert é.
There is a list of Alt Codes available at http://www.alt-codes.net/
Penn State University has an excellent guide to typing in accents and special characters in Windows or Macs. Including Alt codes, Mac codes and how to use the character map/viewer.
These tips can also be applied in other software and web interfaces, as well as in bibliographic software. ☺ = ALT 1