| Quellsystem | Nominativ, Singular | nominative case, singular | |
| Quellsystem(e)s | Genitiv, Singular | genitive case, singular | |
| Quellsystem(e) | Dativ, Singular | dative case, singular | |
| Quellsystem | Akkusativ, Singular | accusative case, singular | |
| Quellsysteme | Nominativ, Plural | nominative case, plural | |
| Quellsysteme | Genitiv, Plural | genitive case, plural | |
| Quellsystemen | Dativ, Plural | dative case, plural | |
| Quellsysteme | Akkusativ, Plural | accusative case, plural |