Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cham duc » pham duc, cham soc, pham duy
hanh lam » thanh lap, hanh kem, hanh va
co sach » bo sach, cuon sach
ty tang » tay tang, ty xang, ty hang
tang xa » trang xa, tang ma, lang xa
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) or (co sach)) ty tang xa hoi. hieu vu cham duc va hanh lam ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (co sach)) ty tang xa hoi. hieu vu cham duc va hanh lam ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (co sach)) ty tang xa hoi. hieu vu cham duc va hanh lam ((cua tre) or (cua te))*.