Perhaps you should try some spelling variations:
va thieu » va thiet, va hieu, va tieu
ve triet » va trien, su triet
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
ly hang » ly quang
ly nang » ky nang, ly vang, ly quang
ve nam » he nam, va nam, le nam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ly nang) OR (ly hang)) xa hoi. hieu ve nam thuc va hanh vi ((ve triet) or (va thieu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ly nang) OR (ly hang)) xa hoi. hieu ve nam thuc va hanh vi ((ve triet) OR (va thieu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ly nang) OR (ly hang)) xa hoi. hieu ve nam thuc va hanh vi ((ve triet) or (va thieu))".
• Adding a wildcard symbol may retrieve word variants: so sach ((ly nang) OR (ly hang)) xa hoi. hieu ve nam thuc va hanh vi ((ve triet) or (va thieu))*.