Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
tong cong » trong cong, cong cong, dung cong
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
chi sach » chinh sach, chieu sach, moi sach
toan cau » toan cao, toan ban, toan tap
co sach » bo sach, cuon sach, hoc sach

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: doi ((chi sach) OR (co sach)) - thanh ((tich va) OR (trinh vat)) tong cong manh toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chi sach) OR (co sach)) - thanh ((tich va) or (trinh vat)) tong cong manh toan cau~".
• Adding a wildcard symbol may retrieve word variants: doi ((chi sach) OR (co sach)) - thanh ((tich va) or (trinh vat)) tong cong manh toan cau*.