Perhaps you should try some spelling variations:
communication costly » communication costs, communication costa, communications costs
money communication » month communication, honesty communication, honest communication
trade developments » trade development, rate developments, price developments
developments a » developments _, developments 4, developments 3
costly trade » costs trade, country trade, costly than
rates money » states money, makes money, rates more
citation a » citation _, citations _, elicitation a
a africa » 1 africa, can africa, em africa
a rates » 4 rates, a rate, gas rates

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

• Adding a wildcard symbol may retrieve word variants: technology _ citation a rates money communication costly trade developments a africa.*.