Perhaps you should try some spelling variations:
development congresses » development processes
century cooperation » century corporation, century competition, country cooperation
technology century » technology center, technology centers, technology centered
oral communication » personal communication
congresses africa » congresses arab, congresses china
cooperation 1 » cooperation _, cooperation a, cooperation 3
4 development » 2 development, 4 developing
costs 4 » costs _, costs a, costs 4.2
2 oral » _ oral, 4 oral

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

• Adding a wildcard symbol may retrieve word variants: technology century cooperation 1 2 oral communication costs 4 development congresses africa.*.