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