Reverse geocoding (lat & lon to address) database is supplied by:
GeoNames.org, licensed under the Creative Commons Attribution 3.0 license License.
OpenStreetMap, licensed under the Open Data Commons Open Database License (ODbL).
Combain has an extensive coverage database, but in a few cases the cell id in the request may be missing from our database.
To improve service in these few cases, we have implemented an automatic cell id fallback to the cellid databases from the following sources:
Mozilla Location Services, provided under the CC0 1.0 Universal license.
Open CellID, provided under the CC-BY-SA 3.0 license.