Perhaps you should try some spelling variations:
bieu hien » dieu hien, dieu khien, bien phien
hieu hien » dieu hien, chieu chien, dieu khien
danh di » danh du, xanh di, danh dien
danh vi » hanh vi, dinh vi, danh va
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
cac su » cach su, cac sau, cac du
su dia » so dia, du dia, su da
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. ((hieu hien) or (bieu hien)) cac su dia ((danh vi) OR (danh di)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. ((hieu hien) OR (bieu hien)) cac su dia ((danh vi) OR (danh di)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. ((hieu hien) or (bieu hien)) cac su dia ((danh vi) OR (danh di)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. ((hieu hien) or (bieu hien)) cac su dia ((danh vi) OR (danh di)) cuu tre*.