Perhaps you should try some spelling variations:
va thieu » va thiet, va hieu, va tieu
nam thuc » nam thuoc, am thuc, nam thu
va triet » va thiet, va trien, ve triet
dan hang » ban hang, van hang, dat hang
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
tu nang » tru nang, tu nong, tu nano
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: su sach tu nang ((xa hoi) or (ma hoa)). hieu ve nam thuc dan hang va ((va triet) or (va thieu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang ((xa hoi) OR (ma hoa)). hieu ve nam thuc dan hang va ((va triet) OR (va thieu)).
• Adding a wildcard symbol may retrieve word variants: su sach tu nang ((xa hoi) or (ma hoa)). hieu ve nam thuc dan hang va ((va triet) or (va thieu))*.