Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh vat » trinh van, trinh luat, sinh vat
thau dau » phan dau, chau au
dau sach » cau sach, dat sach, hau sach
vat dang » van dang, vat dung, va dang
cong van » cong vang, cong san, cong tan
song van » hoang van, trong van, duong van
toan cau » toan cao, toan ban, toan tap

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: "thau dau sach - hanh trinh vat dang ((cong van) OR (song van)) toan cau~".
• Adding a wildcard symbol may retrieve word variants: thau dau sach - hanh trinh vat dang ((cong van) OR (song van)) toan cau*.