Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu viec » nhieu viec, hieu ve, sieu viet
dung doi » huong doi, dung tai, dung co
danh doi » danh di, thanh doi, danh hoa
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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 lang xa hoi. ((hieu viec) or (hieu va)) sach nuoc va ((danh doi) OR (dung doi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. ((hieu viec) OR (hieu va)) sach nuoc va ((danh doi) OR (dung doi)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang xa hoi. ((hieu viec) or (hieu va)) sach nuoc va ((danh doi) OR (dung doi)) cua tre*".