Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
su sach » so sach, vu sach
ty hang » ly hang, ty xang, thi hang
hieu ve » hieu va, hieu van
lai cua » dai cua, hai cua, lai chau
hang x » nang x, hoang xa, chang xu
ve cao » va cao, ve bao, ve cac
cao tu » cao thu, co tu, cao su
tu van » tu va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuat sach) OR (su sach)) ty hang x ho. hieu ve cao tu van hanh lai cua vat~.
• Adding a wildcard symbol may retrieve word variants: ((thuat sach) or (su sach)) ty hang x ho. hieu ve cao tu van hanh lai cua vat*.