Perhaps you should try some spelling variations:
optical communication » optical communications, optic communication, political communication
communication system » communication systems, telecommunication system, communication series
gap developpement » au developpement, de developpement, le developpement
developpement de » developpement des, developpement durable
information pt » information part, information 1, information 1.2
system gap » systems gaps, system gis, system gfr
1 optical » 12 optical, 14 optical, _ optical
de africa » does africa, de america, use africa
pt 1 » pt 2

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

• Adding a wildcard symbol may retrieve word variants: technologies _ information pt 1 optical communication system gap developpement de africa.*.