This is an excellent data base of LW and MW worldwide: www.mwlist.org
According to the website:
This is a radio station database of all Longwave (LW), Medium wave (MW) and Tropical bands stations worldwide. You can browse frequency and location lists, search for stations, and get technical information. If you register, you can use a online logbook, create bandscans, and provide update information to the database editors. This is a free, open and non-commercial hobby project which depends on the cooperation of many individuals.
For LW/MW DXer’s this is a good information source.