Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh do » thanh de, thanh hoa, thanh loi
dang xay » dang van, van xay
cac truc » cau truc, cac tru, cac trung
truc va » thuc va, thuc vat, trung va
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
qua cac » cua cac

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 ty ((nang xa) or (dang xay)) hoi. hieu qua cac truc va ((thanh do) or (thanh pho)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (dang xay)) hoi. hieu qua cac truc va ((thanh do) OR (thanh pho)) su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (dang xay)) hoi. hieu qua cac truc va ((thanh do) or (thanh pho)) su triet*.