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

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) OR (te sach)) ky nang x ho. hieu qua cau luc va ((doan thi) OR (dan 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 ((doan thi) OR (dan 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 ((doan thi) OR (dan thi)) cau tren*.