Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
su tien » su kien, su hien, tu tieng
nang xa » lang xa, nang ma, mang xa
te sach » toc sach
di su » doi su, ki su, da su

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) or (te sach)) ky ((nang xa) or (nang x)) hoi. hieu van cac duc va hanh di su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky ((nang xa) OR (nang x)) hoi. hieu van cac duc va hanh di su tien.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky ((nang xa) or (nang x)) hoi. hieu van cac duc va hanh di su tien*.