Perhaps you should try some spelling variations:
methodology empirical » methods empirical
empirical inflation » empirical information, empirical implication, empirical innovations
communications cost » communications costs, communications cross, communication costs
3 communications » 3 communication, 2 communications, 4 communications
test development » forest development, port development, mena development
development en » developpement en, development menu, development eco
rate file » case file, rate fee, rate firm
cost test » post test, rest test, test test
file 3 » file 13, file 23, file 30

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

• Adding a wildcard symbol may retrieve word variants: methodology empirical inflation rate file 3 communications cost test development en afrique.*.