Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
thuc va » thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ha hoi » hoa hoi, ha noi, va hoi
va nam » van nam, ha nam, va nay
va va » va van, va vua, va vai

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