Galena from Berks County, Pennsylvania, USA
USA | |
| Ref.: Gordon, Samuel G. (1922), Mineralogy of Pennsylvania: 153. |
Pennsylvania Geological Survey (1984, October) Pennsylvania Geology Vol. 15 (5) p2-4 | |
| The Mineralogy of Pennsylvania 1966-1975 Robert C. Smith II, pg. 232, Table 27 |