Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, phan duc
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty hang, ly nang
hieu ve » hieu va, hieu van
vi va » vi van, vai va, vu va
thiet » thieu

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 (ty xang)) xa hoi. hieu ve ((cham duc) or (pham duy)) van hanh vi va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu ve ((cham duc) OR (pham duy)) van hanh vi va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty xang)) xa hoi. hieu ve ((cham duc) or (pham duy)) van hanh vi va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu ve ((cham duc) or (pham duy)) van hanh vi va thiet*.