Perhaps you should try some spelling variations:
tinh hai » tinh thai, tinh chat, trinh han
tinh dai » trinh dai, tinh da, tinh doi
tu sach » thu sach, su sach, te sach
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
ve cam » ve cham, ve cac, va cam

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 ky nang ((mai hoi) or (lai hoi)). hieu ve cam duc va ((tinh dai) OR (tinh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cam duc va ((tinh dai) OR (tinh hai)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((mai hoi) or (lai hoi)). hieu ve cam duc va ((tinh dai) OR (tinh hai)) cua tre*".