| Deszendenztheorie | descension theory evolutionary theory |
| Deszendenzlehre | evolutionary theory |
| Deszendentin | descendant |
| Mengentheorie | set theory |
| Deszendent | descendant |
| Pongidentheorie | Pongidae hypothesis |
| Bedienungstheorie | queue theory queueing theory |
| Dramentheorie | dramatic theory |
| Erkenntnistheorie | epistemology |
| Quantentheorie | quantum theory |
| Wellentheorie | wave model wave theory |
| Zahlentheorie | theory of numbers |
| Knotentheorie | knot theory |
| Zelltheorie | cell theory |
| Automatentheorie | automata theory |
| Bindungstheorie | attachment theory |
| Graphentheorie | graph theory |
| Gruppentheorie | group theory |
| Quantenfeldtheorie | quantum field theory |
| Spieltheorie | game theory |