Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
nang cong » nang song, bang cong, hang cong
dang cong » dung cong
cau sach » hau sach, rau sach, khau sach
cao sach » co sach, ao sach, lao sach
trinh va » trinh van, trinh vat, trinh ve
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((cau sach) OR (cao sach)) - hanh trinh va ((nang cong) OR (dang cong)) dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((cau sach) or (cao sach)) - hanh trinh va ((nang cong) OR (dang cong)) dan toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((cau sach) or (cao sach)) - hanh trinh va ((nang cong) OR (dang cong)) dan toan cau*.