Perhaps you should try some spelling variations:
information class » information classes, information case, information costs
2.1 communication » 2.14 communication, 2.3 communication, 2.7 communication
more information » price information, trade information
developing areas » developing asia, developing east, developing a
technology more » technology moral, technology make, technology mara
4 developing » 3 developing
areas africa » arabs africa, dress africa, farmers africa
class state » class share
state 2.1 » states 2.1, state 2.2, state 2.3
costs 4 » costs _, costs a, costs 4.2

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

• Adding a wildcard symbol may retrieve word variants: technology more information class state 2.1 communication costs 4 developing areas africa.*.