Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
xa thanh » va thanh, ha thanh, ta thanh
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
ty nang » ty xang, ty hang, ly nang
ve cac » va cac
o hoi » co hoi, o hoc, o hai
vi su » va su, ve su, ki 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) OR (ky nang)) o hoi. hieu ((ve cac) or (vien cac)) tuc xa thanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ky nang)) o hoi. hieu ((ve cac) OR (vien cac)) tuc xa thanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ky nang)) o hoi. hieu ((ve cac) or (vien cac)) tuc xa thanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ky nang)) o hoi. hieu ((ve cac) or (vien cac)) tuc xa thanh vi su triet*.