Perhaps you should try some spelling variations:
hieu tieng » viet tieng, dien tieng, tiep tieng
hieu hien » bieu hien, dieu hien, chieu chien
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cac bac » cac bai, cac ban, cac cach
sach tu » sach thu, cach tu, sach ty
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
bac va » ban va, bac ha, bao va
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 tu ((nang xa) or (nang ma)) hoi. ((hieu tieng) or (hieu hien)) cac bac va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nang xa) OR (nang ma)) hoi. ((hieu tieng) OR (hieu hien)) cac bac va hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nang xa) or (nang ma)) hoi. ((hieu tieng) or (hieu hien)) cac bac va hanh di cua tre*.