SQL & PL/SQL

Hello,

I'm running a query using SQL Developer on a table which contains several companies names from many different countries, and one of the checks I need to make to ensure data consistency is to search for all rows which the name of company contains special or non-english characters (like ç, ã, ä as example).

I don't know what can I use to do this. I tried to collate using NLS_SORT but it didn't work.

Is there someway to select only the rows that contain these special or non-english characters, excluding from the results the rows that only have english characters? Please have in mind that we have many languages in this table.

The field I would like to make the conditions on is VARCHAR2.

Please let me know if there is any extra information I should provide you so that you can help me.

Thank you in advance for the help.

Regards,
Luís