Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu viec » nhieu viec, sieu viet, hieu hien
danh doi » thanh doi, dung doi, danh hoa
cua tre » cua te, cuu tre, cua triet
danh di » danh du, xanh di, danh dien
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
sac ky » cac ky, sai ky
su sac » su sach, su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va ((danh doi) OR (danh di)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang xa hoi. ((hieu viec) OR (hieu ve)) sach nuoc va ((danh doi) OR (danh di)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va ((danh doi) OR (danh di)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va ((danh doi) OR (danh di)) cua tre*.