Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
dat tren » dat trong, dua tren
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
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 dat » voi dat, vi dai, va dat
va cau » van cau, va cac, va 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) OR (thuoc sach)) y mang xa hoi. hieu va cau ((xuc van) or (luc van)) anh vi dat tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) y mang xa hoi. hieu va cau ((xuc van) OR (luc van)) anh vi dat tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) y mang xa hoi. hieu va cau ((xuc van) or (luc van)) anh vi dat tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) y mang xa hoi. hieu va cau ((xuc van) or (luc van)) anh vi dat tren*.