Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
tang hanh » tang thanh, dang hanh, nang hanh
cac toi » cac thoi
toc sac » toc sach, toc san, hoc sach
dang xa » dang xay, dang ha, dang va
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sac ky ((dang xa) OR (lang xa)) hoi. hieu hien ((cac toi) or (cac hop)) tang hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky ((dang xa) OR (lang xa)) hoi. hieu hien ((cac toi) OR (cac hop)) tang hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sac ky ((dang xa) OR (lang xa)) hoi. hieu hien ((cac toi) or (cac hop)) tang hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sac ky ((dang xa) OR (lang xa)) hoi. hieu hien ((cac toi) or (cac hop)) tang hanh vi cua tre*.