Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang xa » dang xay, dang ha, dang va
lang xa » lang ha, dang xay, lang van
va hanh » van hanh, va thanh, va danh
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky ((dang xa) OR (lang xa)) hoi. hieu vien cac nuoc va hanh vi ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((dang xa) OR (lang xa)) hoi. hieu vien cac nuoc va hanh vi ((cua te) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky ((dang xa) OR (lang xa)) hoi. hieu vien cac nuoc va hanh vi ((cua te) or (cua tu))*".