Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
dang thi » hoang thi, dang khoi
thi cau » thi chau, thi cu, thi cam
va dang » van dang, va nang, va lang
cac tac » cac toc, cac bac, cac dac
qua cac » cua cac
sach ky » sach y, sach kem, sach hay
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
tac va » tac da, tac xa, tuc va
sac ky » cac ky, sai ky

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

• 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 qua cac tac va dang thi cau 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 qua cac tac va dang thi cau tren~".
• Adding a wildcard symbol may retrieve word variants: tu ((((sach ky) OR (sac ky))) or (sach ty)) lang xa hoi. hieu qua cac tac va dang thi cau tren*.