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

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