Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, dat nuoc, cua nuoc
hieu ve » hieu va, hieu van
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
lang xa » lang ha, dang xay, lang van
vi cua » vai cua, di cua
sac ky » cac ky
cua te » cua tu

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) or (sai ky)) lang xa hoi. hieu ve ((cac nuoc) OR (hoc nuoc)) va danh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sai ky)) lang xa hoi. hieu ve ((cac nuoc) OR (hoc nuoc)) va danh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sai ky)) lang xa hoi. hieu ve ((cac nuoc) OR (hoc nuoc)) va danh vi cua te".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sai ky)) lang xa hoi. hieu ve ((cac nuoc) OR (hoc nuoc)) va danh vi cua te*.