ECHO is a collection of free European databases accessed by telnet. Here is their description file . To connect, type 'ECHO' as the password at the first prompt, then 1 for english, then select the database. Searching is accomplished using their Common Command Language - start with 'Find ' then 'Show' to retrieve your results. Read their pdf manual for more.
Many databases are unavailable through the major database retailers.
These databases are typically tightly focused, often with a limited audience. Gales Directory of Databases is produced by Gale Research. Further descriptions can be found from Dialog and Datastar . Most large libraries will have a copy - ask for it by name. New editions are released every 6 months.