| Subject | English | German |
| radiat. | S450 spectral source strength | spektrale Quellstärke (particles of energy between E and E + dE emitted per unit time) |
| med. | spectral light source | Spektrallichtquelle |
| phys. | spectral source | spektrale Quelle |
| earth.sc. | spectral source density | spektrale Quelldichte |
| earth.sc. | spectral source strength | spektrale Strahlungsintensität |
| earth.sc. | spectral source strength | spektrale Quellstärke |