Perhaps you should try some spelling variations:
vien dai » hien dai
xa thanh » va thanh, ha thanh, ta thanh
thanh ki » thanh kim, thanh ky, thanh ke
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang ho » nang hoc, nang co, tang ho
ho hoi » hoc hoi, hoa hoi, hoi hoi
ve cac » va cac, vien cac
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 ty nang ho hoi. hieu ((ve cac) or (vien dai)) tuc xa thanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ho hoi. hieu ((ve cac) OR (vien dai)) tuc xa thanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ho hoi. hieu ((ve cac) or (vien dai)) tuc xa thanh ki su triet*.