Perhaps you should try some spelling variations:
models development » model development, module development, model developments
communication cost » communication costs, communication costa, communications costs
4 communication » 3 communication, 5.4 communication, de communication
technology 4.2 » technology 2.2, technology 3.2, technology 4.1
development en » developpement en, development menu, development eco
cost models » cost model, logit models
scarce 4 » scarce 3, scare _, source 4

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

• Adding a wildcard symbol may retrieve word variants: technology 4.2 information d820 scarce 4 communication cost models development en afrique.*.