Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
thien cac » hien cac, thien cau, thieu cac
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
sach tu » sach thu, cach tu, sach ty
nang xa » nang x, lang xa, mang xa
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
cac co » cac cong
sac ky » cac ky, sai ky
cua te » cua tu
co va » co ma, do va, so 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 ((sac ky) or (sach tu)) ((nang xa) OR (nang ma)) hoi. hieu thien cac co va hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (sach tu)) ((nang xa) OR (nang ma)) hoi. hieu thien cac co va hanh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sac ky) or (sach tu)) ((nang xa) OR (nang ma)) hoi. hieu thien cac co va hanh vai cua te".
• Adding a wildcard symbol may retrieve word variants: su ((sac ky) or (sach tu)) ((nang xa) OR (nang ma)) hoi. hieu thien cac co va hanh vai cua te*.