Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
may thoi » gay thoi, may thi, tay thoi
cham hoi » cham voi, cham h'roi, pham hoai
hieu van » hieu va, thien van, lieu va
may hoi » tay hoi, mai hoi, may hmi
sach ty » sach y, sach tu, sach thu
ty mang » ty xang, ty hang, tin mang
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
cam lo » nam lo, cam ly, cam o
va cua » va chua, via cua, ca 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 ty mang ((may hoi) or (may thoi)). hieu van ((cham hoi) or (cam lo)) va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty mang ((may hoi) OR (may thoi)). hieu van ((cham hoi) OR (cam lo)) va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thuat sach ty mang ((may hoi) or (may thoi)). hieu van ((cham hoi) or (cam lo)) va hanh va cua tre*.