Perhaps you should try some spelling variations:
chieu chien » thien chien
hieu hien » bieu hien, dieu hien, dieu khien
dinh vai » dinh van, dinh vi, dinh va
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
ty nang » ky nang, ty hang, ly nang
cua tre » cua te, cuu tre, cua triet
cac bo » bac bo, cac co
bo va » bao va, do va, so va

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