Perhaps you should try some spelling variations:
hieu hien » bieu hien, chieu chien, dieu khien
dieu hien » dieu khien, dieu kien, bieu hien
dinh vai » dinh van, dinh vi, dinh va
tu sach » thu sach, su sach, te sach
cac lop » cac hop, cac loai
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach ty
cac lo » cac co, cac bo, cac ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((hieu hien) OR (dieu hien)) ((cac lo) OR (cac lop)) va dinh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((hieu hien) OR (dieu hien)) ((cac lo) or (cac lop)) va dinh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((hieu hien) OR (dieu hien)) ((cac lo) or (cac lop)) va dinh vai cua tre*.