Perhaps you should try some spelling variations:
optical communication » optical communications, optic communication, political communication
communication model » communication media
development plan » development plans, development planning, development policy
sbm development » cdm development, dam development, term development
plan african » pan african, plan africa, class african
d optical » _ optical, 3 optical, 4 optical
model sbm » model sem, model sm, model some
gap d » gap _, gap 4, gap a

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

• Adding a wildcard symbol may retrieve word variants: technologies _ information gap d optical communication model sbm development plan african.*.