Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
thi cuc » tai cuc
anh thi » anh tho, dinh thi, dang thi
van anh » van thanh, tuan anh, van minh
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
cuc tre » duc tre, cua tre, cuu tre
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
co hai » co dai, co hoi, o hai
o hoc » co hoc, mo hoc, so hoc

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 nang ((o hoc) or (co hai)). ((hieu ve) OR (hieu va)) cac xuc van anh thi cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoc) OR (co hai)). ((hieu ve) OR (hieu va)) cac xuc van anh thi cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoc) or (co hai)). ((hieu ve) OR (hieu va)) cac xuc van anh thi cuc tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoc) or (co hai)). ((hieu ve) OR (hieu va)) cac xuc van anh thi cuc tre*.