Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thanh van » thanh san, thanh toan, thanh phan
su triet » su viet, su tien, ve triet
thanh va » hanh va, thanh ha, thanh ve
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cac tac » cac toc, cac bac, cac dac
tac xa » tuc xa, tac da
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang o hoi. hieu vien cac tac xa ((thanh va) or (thanh van)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang o hoi. hieu vien cac tac xa ((thanh va) OR (thanh van)) su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hoi. hieu vien cac tac xa ((thanh va) or (thanh van)) su triet*.