Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
giao quoc » giao duc, giac duoc, cao quoc
cua viet » ca viet, hoa viet, cua vat
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve giao » te giao, viet giao, van giao

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((nang ma) or (lang xa)) hoi. hieu ve giao quoc gia thanh tai ((cua viet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang ma) OR (lang xa)) hoi. hieu ve giao quoc gia thanh tai ((cua viet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang ma) or (lang xa)) hoi. hieu ve giao quoc gia thanh tai ((cua viet) or (su triet))*.