. 2020 Sep 1;119(4):504–516. doi: 10.1097/HP.0000000000001146
Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a "work of the United States Government" for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.
Fig. 3.
Fallout contours (E12, TOA) (Quinn 1987).