Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cham loc » cham soc, chon loc, cham o
cau tren » cu tren, dau tren, ca tren
tinh vi » trinh vi, tinh voi, dinh vi
loc may » hoc may, loc mau, loai may
tinh va » tich va, trinh van, trinh vat
va cham » va chat, va tham
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
o hoi » co hoi, o hai, o hoa
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: thu sach v nang ((o hoi) OR (o hoc)). lieu va cham loc may ((tinh vi) or (tinh va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach v nang ((o hoi) OR (o hoc)). lieu va cham loc may ((tinh vi) OR (tinh va)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach v nang ((o hoi) OR (o hoc)). lieu va cham loc may ((tinh vi) or (tinh va)) cau tren".
• Adding a wildcard symbol may retrieve word variants: thu sach v nang ((o hoi) OR (o hoc)). lieu va cham loc may ((tinh vi) or (tinh va)) cau tren*.