Perhaps you should try some spelling variations:
development constraints » development countries
information class » information classes, information case, information costs
de communication » mobile communication, online communication
2.3 development » 2 development, 2015 development, 1 development
constraints a » constraints _, constraints 3, constraints 4
technology 2 » technology _, technology 1, technology 3
class debate » grass debatte, class state, care debate
debate de » debates de, debate we, debatte der
costs 2.3 » costs 4.2, costs 4.4

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

• Adding a wildcard symbol may retrieve word variants: technology 2 information class debate de communication costs 2.3 development constraints a.*.