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