Perhaps you should try some spelling variations:
thien van » thi van
thanh van » thanh san, thanh toan, thanh phan
ve triet » va trien, su triet
thi nang » thi cong, ki nang, thi hanh
hieu van » hieu va, lieu va, hieu ve
thanh va » hanh va, thanh ha, thanh ve
sach thi » sach thu, sach tai, sach thieu
tu sach » thu sach, su sach, te sach
cac tac » cac toc, cac bac, cac dac
tac xa » tuc xa, tac da
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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 thi nang o hai. ((hieu van) or (thien van)) cac tac xa ((thanh va) or (thanh van)) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi nang o hai. ((hieu van) OR (thien van)) cac tac xa ((thanh va) OR (thanh van)) ve triet.
• Adding a wildcard symbol may retrieve word variants: tu sach thi nang o hai. ((hieu van) or (thien van)) cac tac xa ((thanh va) or (thanh van)) ve triet*.