Perhaps you should try some spelling variations:
china's communications » china communications, china communication, crisis communications
trade development » software development
development works » development work, development workshop, development network
der variation » de variation, does variation, die variation
works africa » towns africa
6 law » 6 laws, _ law, a law
6 la » a la, 6 a, _ la
theorie » theories

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "theorie der variation ((6 law) OR (6 la)) china's communications _ trade development works africa.~".
• Adding a wildcard symbol may retrieve word variants: theorie der variation ((6 law) OR (6 la)) china's communications _ trade development works africa.*.