Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
danh doi » danh di, thanh doi, dung doi
dang xay » dang van, van xay
hieu va » lieu va, hieu qua
doi cua » dai cua, hoi cua
va danh » va dinh, va dan, va hanh
sach ky » sac ky, sach y, sach kem
xay hoi » xa hoi, tay hoi, cay phoi
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet

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 ky) OR (sach ty)) dang xay hoi. ((hieu viec) or (hieu va)) sach nuoc va danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) dang xay hoi. ((hieu viec) OR (hieu va)) sach nuoc va danh doi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) dang xay hoi. ((hieu viec) or (hieu va)) sach nuoc va danh doi cua tre*".