Perhaps you should try some spelling variations:
optical communication » optical communications, optic communication, political communication
high development » highway development, rights development, dough development
development case » development china
2.1 information » 3.1 information
technology 2.1 » technology 2.2, technology 3.1, technology 1
from optical » from optimal, from optional, from apical
case africa » cases africa, care africa, curse africa
gap from » gaps from, map from, gdp from

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

• Adding a wildcard symbol may retrieve word variants: technology 2.1 information gap from optical communication a high development case africa.*.