Perhaps you should try some spelling variations:
thanh luc » thanh luu, than luc, nhan luc
chay tren » thai tren, ca tren, cau tren
qua thanh » quan thanh, cua thanh, qua than
lai chay » lai chau, lam chay, lai chang
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
luc van » luoc van, luu van, duc van
tu sach » thu sach, te sach, tu cach
nang ma » tang ma, nang cao, mang may
su sach » so sach, vu sach
sang ma » tang ma, sang tao, mang may

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 (su sach)) v ((nang ma) OR (sang ma)) hoi. hieu qua thanh luc van hanh lai chay tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) v ((nang ma) OR (sang ma)) hoi. hieu qua thanh luc van hanh lai chay tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) v ((nang ma) OR (sang ma)) hoi. hieu qua thanh luc van hanh lai chay tren*".