* Generator: [DEM Net Elevation API](https://elevationapi.com)
* Digital Elevation Model: [GEBCO Compilation Group (2019) GEBCO 2019 Grid (doi:10.5285/836f016a-33be-6ddc-e053-6c86abc0788e)](https://www.gebco.net/data_and_products/gridded_bathymetry_data/gebco_2019/gebco_2019_info.html)
* Imagery: [ThunderForest](https://www.thunderforest.com)