Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, va danh
sach ty » sach y, sach tu, sach thu
cac dai » cac dan, cac bai, can dai
van cac » van hac, van cau, van bac
mai hoi » mai khoi, dai hoi, lai hoi
dai va » mai va
vi cua » vai cua, di cua
sac ky » cac ky, sai ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach ty)) nang ((xa hoi) OR (mai hoi)). hieu van cac dai va hanh vi cua vat~.
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach ty)) nang ((xa hoi) or (mai hoi)). hieu van cac dai va hanh vi cua vat*.