Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cac dac » cac dan, cac dai, cac bac
cac duc » cac du, cao duc, cac nuoc
sach ty » sach tu, sach thu, xach tay
cao hoi » cau hoi, co hoi, cao hoc
di cua » dai cua, doi cua, de cua

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 ty) or (sach y)) nang cao hoi. hieu van ((cac duc) or (cac dac)) va hanh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang cao hoi. hieu van ((cac duc) OR (cac dac)) va hanh di cua vat.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach y)) nang cao hoi. hieu van ((cac duc) or (cac dac)) va hanh di cua vat*.