Perhaps you should try some spelling variations:
tham duc » pham duc, than duc, thach duc
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, tu cach
te sach » toc sach
tham du » thap du, tham do, pham duc
x hoi » xa hoi, o hoi, x ho
vi va » vi van, vai va, vu va

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) or (te sach)) ky nang x hoi. hieu qua ((tham duc) OR (tham du)) van hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x hoi. hieu qua ((tham duc) OR (tham du)) van hanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang x hoi. hieu qua ((tham duc) OR (tham du)) van hanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang x hoi. hieu qua ((tham duc) OR (tham du)) van hanh vi va triet*.