Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
su triet » su viet, su tien, ve triet
thanh va » hanh va, thanh ha, thanh ve
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
van cac » van hac, van cau, van bac
ty nang » ky nang, ty xang, ty hang
cac toc » cac toi, cac nuoc, cac thoi
toc xa » tuc xa, toc ta, hoc xa
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 ty nang o hai. hieu van cac toc 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 hai. hieu van cac toc xa ((thanh va) OR (thanh van)) su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hai. hieu van cac toc xa ((thanh va) or (thanh van)) su triet*.