Perhaps you should try some spelling variations:
der generationstheorie » die generationstheorie, und generationstheorie, der integrationstheorie
generationstheorie 2 » generationstheorie 1.1, generationstheorie 1.9, generationstheorie 5.4
integration social » international social
4 integration » 3 integration, 2 integration, 4.1 integration
supply der » supply order, supply under, supply siders
support 4 » support _, support a, support 3.4

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( support 4 integration social. ) OR ( supply der generationstheorie 2. ))~.
• Adding a wildcard symbol may retrieve word variants: (( support 4 integration social. ) or ( supply der generationstheorie 2. ))*.