Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hanh tai » thanh tai, hang tai, han tai
dai hai » dai han, dai tai, dai thao
dai hoi » dai hoc, dai moi
va tham » van tham, va cham, va thanh
sach ky » sac ky, sach y, sach ty
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
lao va » tao va, cao va, dao va
bao va » bao ve, tao va, ban va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky nang ((dai hoi) or (dai hai)). lieu va tham ((lao va) OR (bao va)) hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((dai hoi) OR (dai hai)). lieu va tham ((lao va) OR (bao va)) hanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((dai hoi) or (dai hai)). lieu va tham ((lao va) OR (bao va)) hanh tai cua tre*".