Perhaps you should try some spelling variations:
communication model » communication media
3.1 communication » 3.1 communications, 3.2 communication, 3.5 communication
cdm developpement » de developpement, du developpement, cdm development
developpement en » developpement et, developpement des, developpement de
inflation gold » inflation good, inflation gerold, inflation gopi
gold rice » gold price, gold rich, gold prices
model cdm » model ccm, model code, model capm
rice 3.1 » rice 2.1, rice 3.3, rice 4.1

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

• Adding a wildcard symbol may retrieve word variants: technology _ inflation gold rice 3.1 communication model cdm developpement en afrique.*.