Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
tang hanh » tang thanh, dang hanh, nang hanh
toc cac » hoc cac, tuc cac, ton cac
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
cac tac » cac toc, cac dac, cac tai
cac bac » cac bai, cac ban, cac cach
cua tre » cua te, cuu tre, cua triet
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 cac ky lang xa hoi. hieu vien ((cac tac) OR (cac bac)) tang hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc cac ky lang xa hoi. hieu vien ((cac tac) OR (cac bac)) tang hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc cac ky lang xa hoi. hieu vien ((cac tac) OR (cac bac)) tang hanh vi cua tre*.