Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
duy sang » duy van, duy can, duy anh
hanh dai » hanh tai, hanh dao, vanh dai
hieu van » hieu va, thien van, lieu va
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
ma hoi » mai hoi, xa hoi, ma hoa
dai va » mai va

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 ((duy sang) or (ky nang)) ma hoi. hieu van cam ((tuc xa) or (thuc va)) hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((duy sang) OR (ky nang)) ma hoi. hieu van cam ((tuc xa) OR (thuc va)) hanh dai va triet.
• Adding a wildcard symbol may retrieve word variants: su sach ((duy sang) or (ky nang)) ma hoi. hieu van cam ((tuc xa) or (thuc va)) hanh dai va triet*.