Perhaps you should try some spelling variations:
doan thi » dan thi, doanh tai, hoang thi
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, tu cach
te sach » toc sach
qua cau » quan cau, qua cac, qua ca
thi cau » thi chau, thi cu, thi cam
luc va » duc va, tuc va
loc va » hoc va

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) or (te sach)) ky nang x ho. hieu qua cau ((luc va) OR (loc va)) doan thi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x ho. hieu qua cau ((luc va) OR (loc va)) doan thi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang x ho. hieu qua cau ((luc va) OR (loc va)) doan thi cau tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang x ho. hieu qua cau ((luc va) OR (loc va)) doan thi cau tren*.