Perhaps you should try some spelling variations:
communication cost » communication costs, communication costa, communications costs
models development » model development, module development, model developments
development niger » development nigeria, development new, development center
relations cost » relations post, relations cross, relations case
technology ii » technology ict, technology 1, technology 3
ii relations » 3 relations, et relations, 1 relations
share mobile » where mobile, change mobile, more mobile
cost models » cost model, logit models
niger birth » niger north, longer birth
cost share » cost shares, cost aware, cost scale

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

• Adding a wildcard symbol may retrieve word variants: technology ii relations cost share mobile communication cost models development niger birth.*.