Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
xach tay » canh tay
va hanh » van hanh, va thanh, ban hanh
mang xa » lang xa, mang may, dang xay
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, dia danh
du cua » duy cua, dau cua, dum cua
ve coc » ve cuoc, ve cac, ve co
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: so ((xach tay) or (sach thu)) mang xa hoi. hieu ve coc luc ((va hanh) OR (va danh)) du cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((xach tay) OR (sach thu)) mang xa hoi. hieu ve coc luc ((va hanh) OR (va danh)) du cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((xach tay) or (sach thu)) mang xa hoi. hieu ve coc luc ((va hanh) OR (va danh)) du cua tu".
• Adding a wildcard symbol may retrieve word variants: so ((xach tay) or (sach thu)) mang xa hoi. hieu ve coc luc ((va hanh) OR (va danh)) du cua tu*.