Perhaps you should try some spelling variations:
information center » information centers, information centre, information content
technologies 2 » technologies _, technologies 4
5.3 developing » 3.3 developing, 1.3 developing, 7.3 developing
developing e » developing _, developing a, developing east
costs 5.3 » costs 15.3, costs 2.3, costs 4.3
e africa » em africa, de africa, eu africa
a set » _ set
a et » a net, a bet, a jet

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "technologies 2 information center ((a et) OR (a set)) communication costs 5.3 developing e africa.~".
• Adding a wildcard symbol may retrieve word variants: technologies 2 information center ((a et) OR (a set)) communication costs 5.3 developing e africa.*.