Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh lai » hanh lam, hanh tai, thanh lap
va cham » va chat, va tham
sach tu » sach thu, cach tu, sach ty
su sach » so sach, vu sach
tu nang » tru nang, tu nong, tu nano
hieu va » lieu va, hieu qua
so hai » son hai, su hai, so ha
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu nang ((o hoc) or (so hai)). hieu va cham ((tu va) or (tu van)) hanh lai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang ((o hoc) OR (so hai)). hieu va cham ((tu va) OR (tu van)) hanh lai su triet.
• Adding a wildcard symbol may retrieve word variants: su sach tu nang ((o hoc) or (so hai)). hieu va cham ((tu va) or (tu van)) hanh lai su triet*.