Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dau tren » dau tien, dat tren, dau tieng
may hoi » may thoi, tay hoi, mai hoi
hieu va » lieu va
xuc van » duc van, vuc van, xuc ban
luc van » luoc van, luu van, duc van
y mang » cay mang
anh vi » hanh vi, anh va, anh ve
vi dau » vi dai, va dau, bi dau

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 y mang may hoi. ((hieu va) OR (hieu qua)) cac ((xuc van) or (luc van)) anh vi dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y mang may hoi. ((hieu va) OR (hieu qua)) cac ((xuc van) OR (luc van)) anh vi dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y mang may hoi. ((hieu va) OR (hieu qua)) cac ((xuc van) or (luc van)) anh vi dau tren".
• Adding a wildcard symbol may retrieve word variants: thu sach y mang may hoi. ((hieu va) OR (hieu qua)) cac ((xuc van) or (luc van)) anh vi dau tren*.