Perhaps you should try some spelling variations:
thi cuu » thi cuc, thi huu, thi cu
dau thi » cau thi, dan thi, dao thi
van hac » van hoc, van ha, van hai
sach ky » sach y, sach ty, sach kem
van cac » van cau, van bac, dan cac
lang xa » lang ha, dang xay, lang van
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va
va dau » va dao

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