Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hanh vai » hanh vi, hanh va, hanh tai
cham hoi » cham voi, cham h'roi, pham hoai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
tu tang » tuc tang, tu trang, tu tong
cua tre » cua te, cuu tre, cua triet
cam lo » nam lo, cam ly, cam o
ma hoi » xa hoi, ma hoa, me hoi

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 tu tang ((ma hoi) OR (mai hoi)). hieu va ((cham hoi) or (cam lo)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach tu tang ((ma hoi) OR (mai hoi)). hieu va ((cham hoi) OR (cam lo)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach tu tang ((ma hoi) OR (mai hoi)). hieu va ((cham hoi) or (cam lo)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach tu tang ((ma hoi) OR (mai hoi)). hieu va ((cham hoi) or (cam lo)) va hanh vai cua tre*.