Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
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
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 (((sach ty) OR (sach tu)))) 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 (((sach ty) OR (sach tu)))) 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 (((sach ty) OR (sach tu)))) lang xa hoi. hieu ve cac tu va hanh vi cu tren".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (((sach ty) OR (sach tu)))) lang xa hoi. hieu ve cac tu va hanh vi cu tren*.