Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu viec » nhieu viec, hieu ve, sieu viet
dang xay » dang van, van xay
cua tre » cuu tre, cua triet, dua tren
danh ca » dan ca, doanh cua, danh cho
va danh » va dinh, va dan, va hanh
cac duc » cac du, cao duc, cac dac
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky dang xay hoi. ((hieu hien) or (hieu viec)) cac duc va danh ca ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xay hoi. ((hieu hien) OR (hieu viec)) cac duc va danh ca ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang xay hoi. ((hieu hien) or (hieu viec)) cac duc va danh ca ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xay hoi. ((hieu hien) or (hieu viec)) cac duc va danh ca ((cua tre) OR (cua te))*.