Perhaps you should try some spelling variations:
thanh thai » thanh hai, thanh tai, nhanh thai
thai cua » than cua, tai cuc, tri cua
va thanh » gia thanh, ban thanh, va tinh
cham duc » pham duc, pham duy, phan duc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
dai hoa » dai khoa, dai hoc, dai hoi
cai hoi » cau hoi, dai hoi, cai hoa
cua tre » cua te, cuu tre, cua triet

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 ky nang ((cai hoi) or (dai hoa)). hieu va ((cham duc) OR (cham soc)) va thanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((cai hoi) OR (dai hoa)). hieu va ((cham duc) OR (cham soc)) va thanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((cai hoi) or (dai hoa)). hieu va ((cham duc) OR (cham soc)) va thanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((cai hoi) or (dai hoa)). hieu va ((cham duc) OR (cham soc)) va thanh thai cua tre*.