Perhaps you should try some spelling variations:
communications costs » communication costs, communications _
imperfections trade » imperfect trade, imperfections a
14 communications » 10 communications, 14 communication, 4 communications
4 imperfections » _ imperfections, _ imperfection, 6 imperfection
trade secrets » trade sectors
developing li » developing ai, developing l2, developing cil
technology 4 » technology _, technology 1, technology 3
4 developing » 3 developing
secrets 14 » secrets _, secrets do, secrets i
li afrique » l afrique, en afrique
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 4 imperfections trade secrets 14 communications costs 4 developing li afrique.*.