Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va manh » van manh, va danh, va hanh
hai cuu » hai cua, hai cuc, thai cua
hai chu » hai chau, hoi chu, hai chi
va cao » va cac, va co, va dao

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)) xa hoi. hieu va cao duc va manh ((hai cuu) or (hai chu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ky nang)) xa hoi. hieu va cao duc va manh ((hai cuu) OR (hai chu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ky nang)) xa hoi. hieu va cao duc va manh ((hai cuu) or (hai chu)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ky nang)) xa hoi. hieu va cao duc va manh ((hai cuu) or (hai chu)) tre*.