Perhaps you should try some spelling variations:
thanh luc » thanh luu, than luc, nhan luc
lai chay » lam chay, lai chang, loai chat
van hanh » van thanh, ban hanh, van anh
va thanh » gia thanh, ban thanh, va tinh
luc van » luoc van, luu van, duc van
tu sach » thu sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang

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