Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
thu sach » thuat sach, thuoc sach, thu hoach
hieu va » lieu va, hieu qua
tu sach » su sach, te sach, tu cach
lang xa » lang ha, dang xay, lang van
y lang » o lang, _ lang, tay lang
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
vi dau » vi dai, va dau, bi dau
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: ((tu sach) OR (thu sach)) y lang xa hoi. hieu va cau ((xuc va) or (tuc va)) hanh vi dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y lang xa hoi. hieu va cau ((xuc va) OR (tuc va)) hanh vi dau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) y lang xa hoi. hieu va cau ((xuc va) or (tuc va)) hanh vi dau tren*".