Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang tai » hang tai, tang tai, sang tai
van hanh » van thanh, ban hanh, van anh
hanh ki » hanh vi, hanh ky, hanh kien
vuc van » duc van, luc van, thuc van
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
tai hoi » tai khoi, dai hoi, tai hai
vu nang » vuc nang, va nang, vu dang
va cao » va cac, va co, va dao
va cai » va cac, va bai, va dai
ki su » ky su

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 vu nang tai hoi. hieu ((va cai) or (va cao)) vuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu nang tai hoi. hieu ((va cai) OR (va cao)) vuc van hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu nang tai hoi. hieu ((va cai) or (va cao)) vuc van hanh ki su triet*.