Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
dai hoi » dai hai, dai moi
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
chat lo » chat co, chat bo, chat vo
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
lo va » lo van, lao va, ly 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) or (sac ky)) nang ((dai hoi) OR (dai hoc)). hieu va chat lo va hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sac ky)) nang ((dai hoi) OR (dai hoc)). hieu va chat lo va hanh thai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) or (sac ky)) nang ((dai hoi) OR (dai hoc)). hieu va chat lo va hanh thai cua tre*".