Perhaps you should try some spelling variations:
sach ky » sach y, sach kem, sach hay
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cu tren » tu tren, dua tren
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du
vi cu » vi su, vi xu, vi du

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